Notice: Hayes Microcomputer Products, Inc. reserves the right to make improvements to the product described in this manual at any time and without notice. Hayes, the Hayes icon, the Hayes logo, the Hayes '302 Escape Sequence Patent icon, V-series, Smartmodem, Smartcom, OPTIMA and ACCURA are trademarks of Hayes Microcomputer Products, Inc. V.FC is a trademarks of Rockwell International Corporation. MNP is a trademark of Microcom, Inc. Other trademarks mentioned in this document are trademarks of their respective companies. This document is copyrighted. All rights are reserved. This document may not, in whole or part, be copied, photocopied, reproduced, translated or reduced to any electronic medium or machine-readable form without prior consent, in writing, from Hayes Microcomputer Products, Inc. Copyright 1993 Hayes Microcomputer Products, Inc. All rights reserved. Printed in U.S.A. Note: This version of the "Hayes AT Command Reference for OPTIMA and ACCURA Products" is a special version edited for bulletin-board downloading. As a plain ASCII character file, it therefore does not contain the graphic elements provided in the printed version. The following graphic characters are used to denote the start of Chapters, 1st Level Headings, 2nd Level Headings, and Table Headings: Chapter Headings are preceded by: ========================================================================= 1st Level Headings are preceded by: ************************************************************************* 2nd Level Headings are preceded by: +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Table Headings are separated from table listings by: ------------------------------------------------------------------------- ========================================================================= Table of Contents Chapter 1: Introduction Scope Organization of This Document Conventions Hex Notation Chapter 2: Basic Command Interface Overview Modes DTE Interface Speeds AT Speed Autobaud Line Speed Connect Speed Response Speed Character Formats General Stop Bits Length And Parity Command Processing Overview Command Process AT Entry Command Entry And Editing Command Delineation A/ The Repeat Command Command Execution Command Validity Information Text Result Codes Execution Time Assumed Zero Suffixes Out-of-Range Suffixes Chapter 3: Extended Command Syntax General Action Commands Command Syntax Test Command Invalid Syntax Parameter Commands Write Parameter Value Read Parameter Value Test Parameter Parameter Values Command Termination Strings Compound Value Strings Allowed Characters Spaces Special Value Formats Chapter 4: AT Commands General A - Answer Command Bn - Communications Options D - Dial Command En - Select Command Character Echo Option Hn - Control The Switchhook I0 - Identify The Product Code I2 - Perform ROM Checksum Test I7 - Version Number Ln - Select Speaker Volume Level Mn - Select Speaker Function Option Nn - Select Negotiate Handshake Option On - Go Online Command P - Select Pulse Dialing Method Qn - Select Result Code Option Sn= - Write To An S-Register Sn? - Read An S-Register T - Select Tone Dialing Method Vn - Select Response Format Option Wn Select Extended Result Code Xn Select Call Progress Option Yn Select Long Space Disconnect Option Zn Perform Soft Reset &An - Select Originate/Answer Role For Autoanswer &Cn - Select Data Carrier Detect Option &Dn Select Data Terminal Ready Option Dumb, switched Smart AT, switched Timing of DTR Off-To-On Transitions Timing of DTR On-To-Off Transitions DTR-Initiated Hard Reset (&D3 in effect) &F - Load Factory Default Profile &Gn - Select Guard Tone Option &Kn - Select Flow Control Option Transparent flow control &Pn - Select Pulse Dialing Parameters &Qn - Select Communications Mode Option &Rn - Select RTS/CTS Option &Sn - Select Data Set Ready Option &T0 - Terminate Test In Process &T1 - Initiate Local Analog Loopback &T3 - Perform Local Digital Loopback &T4 - Enable Granting Of RDL Requests &T5 - Deny Granting Of RDL Requests &T6 - Initiate Remote Digital Loopback &T7 - Initiate RDL With Self Test &T8 - Local Loopback With Self Test &T19 - Perform RTS/CTS Cable Test &Un - Disable Trellis Coding &V - View Configuration Profiles &Wn - Store Active Profile &Xn - Select Sync Transmit Clock Source &Yn - Select Stored Profile For Hard Reset &Zn= - Store Telephone Number , Perform Pause = - Write To An S-Register ? - Read An S-Register P - Select Pulse Dialing T - Tone Chapter 5: Result Codes Basic Result Codes Extended Result Codes Chapter 6: S-Registers Introduction Scope Command Lines Default Value Types Behavior Of Unimplemented S-registers Classifications Of S-registers Value Evaluation Rules Summary Of S-register Behaviors S0 - Ring After Which To Answer S1 - Ring Count S2 - Hayes Escape Character S3 - Carriage Return Character S4 - Line Feed Character S5 - Backspace Character S6 - Wait Before Blind Dialing S7 - Wait For Carrier S8 - Pause Time For Comma S9 - Carrier Recovery Time S10 - Lost Carrier Hang Up Delay S11 - DTMF Dialing Speed S12 Hayes Escape Guard Time S16 - Test in Progress S18 - Modem Test Timer S19 - AutoSync Options S25 - Detect DTR Change S26 - RTS To CTS Delay Interval S30 - Inactivity Timeout S31 - XON Character S32 - XOFF Character S36 - Negotiation Failure Treatment S37 - Desired DCE Line Speed S38 - Hang-up Timeout S43 - Current Line Speed S44 - Framing Technique S46 - Protocol/Compression Selection S48 - Feature Negotiation Action S49 - Buffer Low Limit S50 - Buffer High Limit S70 - Maximum Number of Retransmissions S73 - No Activity Timeout S82 - Break Selection S86 - Connection Failure Cause Code S91 - Select Dial-up Line Transmit Level S95 - Extended Result Code Bit Map S97 - V.32 Late Connecting Handshake Timing S105 - Frame Size S108 - Signal Quality Selector S109 - Carrier Speed Selector S110 - V.32/V.32 bis Selector S113 - Calling Tone Control S121 - Use of DTR S141 - Detection Phase Timer S142 - Online Character Format S144 - Autobaud Speed Group Selection Chapter 7: Modem States Modem Functions Major States Chapter 8: Processes and Procedures Answering Process Carrier Detection Dialing Process Hayes Improved Escape Sequence with Guard Time Handshaking Process Hang-up Process Resets Power On Reset Hard Reset Soft Reset Key Press Abort Online State Online Command State Response To Ringing General RI Lead. S1 Register. RING Result Code. RDL Process Chapter 9: FAX Functions Introduction Philosophy Modem FAX Modes FAX Class 1 Mode DTE Interface Leads General FAX Operation FAX Commands and Responses FAX Identification Responses FAX Commands in Data Mode Escape From On-line State DTE Interface Speed FAX Class 1 General Commands Answer Handshake +FAE Automatic Data/FAX Handshake Result Codes Flow Control Data Commands and Registers Commands Special Call Setup Conditions S Registers References Chapter 10: Dumb Mode General Dumb Mode Characteristics Making Calls The Dumb Strap Chapter 11: DTE Interface General Clock Leads (pins 15, 17, 24) Clear to Send (CTS) - pin 5 Data Set Ready (DSR) - pin 6 Data Terminal Ready (DTR) - pin 20 High Speed (HS) - pins 12 and 23 Receive Data (RD) - pin 3 Ring Indicator (RI) - pin 22 Received Line Signal Detector (RLSD) - pin 8 Request to Send (RTS) - pin 4 Send Data (SD) - pin 2 Chapter 12: Modem LEDs AA - Auto Answer CD - Carrier Detection HS - High Speed MR - Modem Ready OH - Off Hook RD - Receive Data SD - Send Data TR - Terminal Ready Chapter 13: Relays Line Phone ========================================================================= Chapter 1 Introduction ************************************************************************* Scope This document contains information on the Hayes Strandard AT Command Set for the Hayes OPTIMA and ACCURA modem products including the V.FC (TM) (Fast Class) type modems. Modems that support the Rockwell 28.8 kbit/second modulation are identified as V.FC in this document. Some features mentioned in this Reference are specific to OPTIMA or ACCURA products, please check the documentation supplied with your modem to determine which features are supported by the modem. ************************************************************************* Organization of This Document This chapter offers introductory information. Subsequent chapters cover the following: * Command syntax * Extended command syntax * AT commands * Result codes * S-registers * Modem states * Processes * Fax transfers * Dumb mode * Leased-line mode * DTE interface signals * Modem lights * Modem relays. *************************************************************************** Conventions The modem offers numerous command modes such as echo/no-echo, verbose/numeric, etc. In the following chapters, assume that certain command modes are in effect to facilitate the discussion of the many features of the product. In effect means either the command has been sent to the modem or the current online communication mode is what the command would have selected. The communication mode may be the result of the handshake process and not due to the indicated command being sent to the modem. Unless specified otherwise, assume that command echo (see the E1 command), the not-quiet mode (see the Qn command), and the verbose result codes (see the V1 command) are in effect. Refer to the En, Qn, and Vn commands to predict modem behavior in other cases. Also, if a CONNECT result code is referred to, the remainder, if any, of the result code (e.g., CONNECT 9600) may have been omitted for generality. Refer to the Xn and Vn commands for additional details on how actual CONNECT result codes appear in specific situations. In various places in the text, the symbols , , and have been used to represent the carriage return character, the line feed character, and the backspace character respectively. Generally speaking, the symbols [, ], <, and > are part of conventions that are used only to assist in the documentation process. In the description of the syntax of commands, the following convention is used: AT [cmds] X [parameter] [cmds] The spaces are not required; they are used to clearly depict the individual elements in the syntax description. AT is always at the beginning of an AT command line, and is always at the end of a command line. The text after the AT is the subject command whose syntax is being described. The [parameter] indicates that this command may have certain character(s), usually numerals, that are optionally part of the command. If it were depicted as , then the parameter value would be a mandatory part of the subject command. The [cmds] means that it is allowed, in general, to place other legal commands before or after the subject command. Some commands cannot be followed by other commands on the same command line. In the case depicted above, the presence of [cmds] after the subject command means that it may be followed by other legal commands in the same command line. ************************************************************************* Hex Notation The symbol $ is used in this document to identify a hex number. For example, $3F means 3F hexadecimal. ========================================================================= Chapter 2 Basic Command Interface ************************************************************************************************** Overview This Chapter describes the basic operation of the modem command interface to the Data Terminal Equipment (DTE). ************************************************************************************************** Modes The modem may be used in one of three modes: * smart AT * switched smart * switched dumb. All discussion of commands applies to both smart modes. When the modem is idle or in Online Command states (smart AT mode), the modem accepts and executes AT commands from the DTE. The modem may also send unsolicited result codes, such as RING and NO CARRIER. While the modem is in smart AT mode and the Online state, it can be caused to go to the online command state by the Hayes Improved Escape Sequence with Guard Time, and sometimes to the idle or online command state by a DTR signal (depending on &Dn). ************************************************************************* DTE Interface Speeds +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ AT Speed The speed of the most recent AT command line entered into the modem from the DTE is called the AT Speed. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Autobaud Autobaud is the process where the modem determines the DTE speed. The modem determines the AT Speed during the AT entry process (either Idle or Online Command State) and during the entry of the A/ command (except in FAX modes). In FAX modes (when +FCLASS=1), the modem autobauds. The modem normally recognizes commands sent by the DTE at 300, 1200, 2400, 4800, 7200, 9600, 14400, 19200, 28800, 38400, 57600, 115200, and 230400 bit/second. Register S144, if supported, can change this list of speeds. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Line Speed The speed at which your Hayes modem communicates with the remote modem (after carrier handshaking) is called the Line Speed. The line speed is determined by a negotiation process during the carrier handshake between the two modems. Refer to Chapter 8 "Handshaking Process" for details. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Connect Speed The Connect Speed is the DTE speed indicated by the CONNECT result code. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Response Speed The speed that the modem uses for responses to the DTE is called the Response Speed. After a reset (power-up reset, etc.), the Response Speed is set equal to the AT Speed at which the last &Wn command was given. The Response Speed is set to the AT Speed each time a command is entered from the DTE. The Response Speed should be set to the connect speed when a call is connected after the CONNECT result code is sent to the DTE. The Response Speed should be set to the AT Speed when the modem enters the idle state after a call is cleared. ************************************************************************* Character Formats +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ General The modem determines the DTE character format during the AT entry process. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Stop Bits Commands may be sent to the modem with one or two stop bits: only the first stop bit performs any function, and the second is ignored. The modem's responses to the DTE always has two stop bits. This is true in the Idle and the Online Command State. Data characters that are transmitted and received between the DTE and the modem has the number of stop bits preserved except as modified due to overspeed or underspeed conditions between the modems. The data bits may be modified when the sending modem has to delete stop bits and the receiving modem shaves (shortens) the stop bits to correct for an overspeed or an underspeed condition. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Length And Parity Commands may be sent to the modem with any of the following data formats: 7-even (7 data bits and even parity bit), 7-odd, 7-mark, 7-space, 8-none, 8-even, 8-odd, and 8-space. The modem ignores the eighth data bit when interpreting command characters. See S142 in Chapter 6 for the online character formats. The word length and format of modem responses to DTE commands are determined by the last AT command entered. The modem uses the same character format as the DTE did during the last AT entry process. ************************************************************************************************** Command Processing +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Overview This section describes the structure of commands (in the form of ASCII characters) from the DTE to the modem and replies from the modem to the DTE. Other modem input signals that may command the modem to take some action are covered in other sections. Many modem parameters and some command memory are stored in user accessible registers called S-Registers. For example, S-register S3 contains the decimal value of the character. S-Register behaviors and definitions are discussed in Chapter 6. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Command Process The command process is defined to start while the modem is in idle or online command states, and the modem detects a start bit from the DTE. The command process ends under any of the three following conditions: (1) when the start bit is not from an AT, at, A/, or a/; or (2) during the 500 microseconds following the result code, transmission is completed; or (3) when certain other processes are started (e.g., handshaking or hard reset). While the command process is active, the modem is determining the AT Speed and parity, accepting commands and corrections, pausing before starting command execution, executing commands (including sending information text to the DTE), sending result codes, and taking a maximum of 500 microseconds to prepare for another command. The modem does not send result codes to the DTE during the command process except for the result codes generated by execution of the command line. The RING result code is suppressed. You can echo characters from the DTE with the E command. If echoed, the modem sends a received character to the DTE. Characters that are ignored are still echoed if you turn on the echo function with command En. All eight bits of an input are echoed, regardless of parity. In some modem implementations, the duration of bits (pulses) of echoed characters may jitter up to 1/16 of the bit duration at the highest DTE speed. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ AT Entry Most commands are sent to the modem in the format: ATxxxx, where is the character defined to represent a carriage return and xxxx represents an AT command. For example, ATE1 enables off-line character echo. The AT can be in upper or lower case but not mixed case. The modem determines the DTE's speed (AT Speed) from the A (or a). The DTE's speed is noted and constitutes an important modifier for some command alternatives. Notes: 1: If the modem determines that the first characters of a new command line are not AT or A/ several times in a row, then the modem may ignore characters from the DTE for up to 2 ms. This is to avoid processing what is likely to be a string of nonsensical characters. 2: Echoed characters and result codes may be sent to the DTE at 500 or 1000 cps instead of at the full DTE speed. 3: The modem may be able to accept the beginning of the next command line immediately after sending a result code. In the following chart the rows represent the cumulative elapsed time required to perform the command. Entry/Edit Modem Execute Send Result Modem from DTE [1] Pause [2] Commands [3] Code Delay [4] ------------------------------------------------------------------------------------------------------------------------- AT commands 125 ms execute result 500 us AT commands ^X 125 ms no action OK 500 us A/ (no commands) 125 ms execute result 500 us Notes: 1: Only the "commands" can be edited. 2: The 125 ms pause permits additional characters from the DTE (e.g., ) that is ignored. 3: The execution of each command includes the modem sending info-text to the DTE before the next command is executed. 4: These 500 microseconds are the maximum delay permitted for the modem firmware to prepare again to accept an AT entry from the DTE. The binary representation of ASCII characters a and A are 1000011P and 1000001P, respectively, with the left most bit sent first and where P represents the parity bit. The modem estimates the duration of the start bit that precedes the leading 1 bit of a or A to determine the DTE's speed. The bits of the A or a and T or t are checked to determine the parity used by the DTE, if any. Characters that may precede the AT are ignored. That is, a string such as ZXDBNMJAAT is interpreted as AT. All characters that follow the AT are treated as commands. The leading A and T of a command line are checked to determine DTE's speed (AT speed) and parity. If the first character of a command line is not an A (or a), it is ignored. If an A is not followed by a T or a /, then the A is ignored. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Command Entry And Editing A command line is a string of characters sent from a DTE to the modem, while the modem is in a command state (idle, on-line command or analog loopback self-test state) that starts with AT and ends with . Spaces in a command line, after AT, are echoed if command echo is enabled but are ignored by the modem, except if part of a string variable input. Spaces are retained in the command line buffer. Spaces sent to the modem by the DTE as part of a string variable are included in the variable. The maximum number of characters in a command line, excluding the , the AT, is 255. If more than 255 characters are entered before the , then the modem returns ERROR after the is entered and does not execute any of the command line. The command buffer is cleared and the modem then waits for a new AT command. The characters of a command line that follow the AT may be corrected by entering backspace characters to erase them. The backspace character is defined by S5, and its default value is the ASCII backspace. The modem determines if a received character is then before any further decoding. This helps to assure and are recognized even if they are defined to be characters that the DTE uses for other purposes. The Ctrl-X character (ASCII CAN) tells the modem to clear its command line buffer and ignore the command line. The Ctrl-X is not followed by a ; it is executed immediately, terminating the command process, and produces the OK result code. The modem's response to a change in DTE's Speed during the entry of a command line is not defined. Except for character echo during command entry, simultaneous communications between the DTE and modem may result in undefined behavior. Therefore, entering commands to the modem during info-text or result codes is not recommended. The results of command entry which interrupts or which is interrupted by a RING or NO CARRIER result code is unspecified. Generally, when the DTE sends a , the modem responds by sending back to the DTE. If E0 is in effect, does not result in any response screen display in any case. This sequence is intended to write over the last-typed character on the terminal screen and leave the cursor positioned there. However, if the DTE sends a string of characters, the modem may not be able to respond to all of them because it attempts to send three characters to the DTE for each received , thereby resulting in undefined behavior due to simultaneous communication between the DTE and the modem. When the DTE sends a to the modem as if to backspace over the T of the AT, then the modem responds by sending T. On a terminal screen, the AT would not appear to be removed. Also, if the DTE had sent at, then the screen would depict aT after responding to a character. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Command Delineation A semicolon may be used to delineate commands on a command line. That is, the end of a command may be marked by a semicolon and other commands may follow on the command line. This use of the semicolon was defined for extended command syntax commands and is valid for all commands. The command line AT; is valid and returns the OK result code. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ A/ The Repeat Command The A/ or a/ command instructs the modem to re-execute the last command line. This command is not preceded by AT and is not followed by . +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Command Execution The modem waits a nominal 125 ms after the terminates command entry before it begins execution of the command line. This allows the DTE to send a after the command line. The and any other characters received during the 125 ms wait are echoed by the modem, but they are ignored. An AT command line consists of one or more individual commands. The execution of the command line consists of the left-to-right execution of each command followed by the reporting of a result code for the entire line. (For more details, refer to "Result Codes" in this Chapter.) The execution of each command in that line may include taking some action, changing a configuration, and/or reporting information text to the DTE. (For more details, refer to the "Information Text" in this Chapter.) Some commands may change nonvolatile information in the mode. There are two special exceptions of the left-to-right execution of the commands in the command line: (1) if the execution of a command produces the ERROR result code, or (2) if the executed command cannot be followed by additional commands, then the remaining commands are ignored. An ERROR is produced during command execution if any of the following conditions occur: * command letter, prefix, or suffix is invalid in the current context (unless otherwise specified), * command qualifier (e.g., = or ?) is invalid in the current context, * command line is too long (see the D command in Chapter 4). +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Command Validity All commands are valid in both the on-line and off-line states unless otherwise noted. ************************************************************************************************** Information Text (Info-Text) The modem's execution of a command line may include sending information text (info-text) to the DTE prior to sending the result code. Some commands produce info-text, others do not. The modem outputs the info-text, if any, for each command before executing the next command on the line. To determine the actual info-text, associated with a specific command, refer to the command definitions in Chapter 4. Each info-text message may be preceded and followed by depending upon which Vn command is in effect. Refer to the Vn command in Chapter 4 for formatting rules. Note that an info-text message may contain multiple lines, and the 's between these lines are not affected by Vn (although they are still programmed by registers S3 and S4, respectively). Several commands have info text that violates these rules, however, in order to assure backwards compatibility of Hayes products. The exception is the I2 command. The formats for I2 are described in Chapter 4. ************************************************************************************************** Result Codes A result code is sent to the DTE in response to the execution of a command line, and it may also result from some other conditions (e.g., RING) as described later. Refer to Chapter 5 for a list of all the possible result codes. Every command line causes one result code message to be sent to the DTE. Normally, this is the OK result code, but there are two general exceptions when it is not: (1) if the execution of a command results in an error, then the ERROR result code is produced, and (2) if call establishment or carrier handshaking function is initiated by a command, then one of the other result codes is produced. These other result codes are specified by the command definitions in the chapters to follow. Result codes may be turned-off or turned-on by the Qn command. Result codes are sent in either a verbose mode or in a numeric short form, depending upon which Vn command is in effect. The modem usually sends one result code, such as OK, to the DTE after executing a command. One exception is after the D command; several result codes may be sent after a connection is established. The DCE accepts a new command 0.5 ms after the last character of a result code or group of result codes has been sent to the DTE. The last character is usually Ctrl-J (line feed). ************************************************************************************************** Execution Time Generally, the execution of most commands proceeds as fast as the modem processor can perform the indicated function. There are, however, constraints on command execution time specified by the command definitions in the chapters to follow. The execution time for each command includes the time required to send info-text (refer to "Information Text" in this Chapter) which is dependent upon the Response Speed. The time required to execute the entire command line also includes the time required to send the result code which is dependent upon the Response Speed. The formula for the total time of execution of a command line follows: TCL = 125 ms + TC1 + TC2 + ... + TRC where: TCn = command execution time including info-text time TRC = result code time. Note: Information text and result code times depend on the Response Speed, the number of characters sent, and which Vn and Qn commands are in effect. ************************************************************************************************** Assumed Zero Suffixes Many commands are of the form Zn, where n is a number. If n is not included, the modem assumes 0 was intended. Thus Z is the same as Z0. ************************************************************************************************** Out-of-Range Suffixes All suffixes outside the specified range cause an ERROR result code and abort the command (and the rest of the command line). Chapter 4 lists suffixes for each command. ========================================================================= Chapter 3 Extended Command Syntax ************************************************************************************************** General Extended commands are action or parameter commands for which a special syntax is used. This chapter describes the syntax rules. Extended commands may set DCE parameter values (parameter commands) or initiate actions (action commands). Action commands may be accompanied by parameter values that affect the outcome of the command. Action commands may be executed or tested. Parameters may be set, read, or tested. ************************************************************************************************** Action Commands +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Command Syntax [=] or [=] Action commands may be accompanied by values (numbers) or strings upon which the command acts. If an extended command is supported, the DCE executes the command as defined in the command description. Otherwise, the DCE returns the ERROR result code. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Test Command ----------------------------------------------------------------------------------------------------------------------------- Syntax =? This command is sent by the DTE to determine if the named command is implemented in the DCE, and, if so, the range of values supported. If the named command is supported, the DCE returns the OK result code; ERROR otherwise. If the command supports a range of values or compound value strings, the DCE reports the range of values or compound value string as described below, then returns the OK result code. The supported values are presented in information text format, as an ordered list preceded by a ( (left parentheses character) and followed by a ) (right parentheses character), ASCII 40 and 41 (decimal). If the value is a compound one, the supported values are reported, enclosed in parentheses and separated by commas. An ordered list consists of a single value, a set of values separated by commas, or as two values separated by a hyphen to denote an inclusive range of values. An example DCE response to a parameter test is: (0-255),(0-2,5) +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Invalid Syntax The syntax ? is used to read a parameter value. If this syntax is used with an action command, the DCE returns the ERROR result code. ************************************************************************************************** Parameter Commands +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Write Parameter Value Syntax = or =. If the value or value string is supported, the parameter is set to the indicated value and the DCE returns the OK result code. Otherwise the DCE returns the ERROR result code. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Read Parameter Value Syntax ? ----------------------------------------------------------------------------------------------------------------------------- If the command is supported the DCE returns the current value of the parameter, followed by the OK result code. Otherwise, the DCE returns the ERROR result code. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Test Parameter ----------------------------------------------------------------------------------------------------------------------------- Syntax =? This is sent by the DTE to determine the parameter values supported by the DCE. If the command is supported, the DCE returns the supported parameter values, using the information text format, as an ordered list preceded by a ( (left parentheses character) and followed by a ) (right parentheses character), ASCII 40 and 41 (decimal). If the value is a compound one, the supported values are reported, enclosed in parentheses and separated by commas. An ordered list consists of a single value, a set of values separated by commas, or as two values separated by a hyphen to denote an inclusive range of values. An example DCE response to a parameter test is: (0-255),(0-2,5) If the command is not supported, the DCE returns the ERROR result code. ************************************************************************************************** Parameter Values Each parameter or action command that takes parameters is defined as taking numeric or string values or a combination of both. Parameter values may be single or compound (more than one). The DCE returns the ERROR result code if the DTE sends an invalid parameter string. Numeric parameter values may be expressed in hexadecimal or decimal, as prescribed by the individual command definitions. ************************************************************************************************** Command Termination All extended commands are terminated by an ASCII semicolon (decimal 59) or CR character (decimal 13). More commands may follow the semicolon. ************************************************************************************************** Strings When a string is to be used by an action command or used as a parameter, the string is appended to the command name by adding an equals sign (=) to the command name, with no intervening spaces, followed by the string enclosed in quote symbols ("). If the quote symbol is to be included as part of the string, the symbol is used twice. For example "abcd""hello""" includes the string "hello" within the quoted string, producing the string: abcd"hello". ************************************************************************************************** Compound Value Strings Several values or strings may be associated with an extended command by placing them serially on the command line with commas between the values or strings. An example is the following: =,,"" ************************************************************************************************** Allowed Characters Strings consist of the ASCII characters space through tilde (decimal 32 through 126). Control characters with decimal values less than 32 are not allowed and are ignored with the exception of . ************************************************************************************************** Spaces Spaces between = and or are ignored by the DCE. Spaces within a string are considered part of the string. Extended command name and its equals sign (=) do not have intervening spaces. ************************************************************************************************** Special Value Formats Values may have special formats if so defined by an extended command description. For example, a value may have two parts as in the following format: 2:4. ========================================================================= Chapter 4 AT Commands ************************************************************************************************** General With a few exceptions, command names contain a prefix (optional), a letter, and a suffix (optional). Prefix &, %, etc. Letter A, B, etc. Suffix a number, such as 5 Following are several examples: Example: &K5 prefix = & letter = K suffix = 5 Example: D letter only Example: I0 letter and suffix In the following specifications, the suffix may be represented generally by the letter n. Do not insert spaces in command names. The modem ignores spaces between commands. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ A - Answer Command ---------------------------------------------------------------------- Command Line Format AT [cmds] A Suffix Values none Factory Default N/A Stored by &Wn N/A Displayed by &V N/A Description The A command instructs the modem to execute the Answer Process, which may quickly lead to executing the Handshaking Process. Refer to "Answer Process" and "Handshaking Process" in Chapter 8. The A command is not valid in the Online Command State or if either &Q2 or &Q3 is in effect. Result Codes CONNECT - if a connection is established. (Refer to "Handshaking Process" in Chapter 8.) NO CARRIER - if a connection cannot be established or if aborted by a character from the DTE. (Refer to the Answer Process and the "Handshaking Process" in Chapter 8.) ERROR - if in Online Command State or &Q2 or &Q3 is in effect when A is issued OK - if aborted by DTR ON-to-OFF whenever certain combinations of &Dn and &Qn are in effect. Refer to the "&Dn" command definition in this Chapter. Execution Time See "Answer and Handshake Processes" in Chapter 8. DTE Interface Lines Affected DSR, RLSD, HS (pin 12 and pin 23). LEDs Affected OH, CD, HS. Aborting events "Key-press abort" aborts Answer and Handshaking Processes. DTR ON-to-OFF aborts Answer and Handshaking whenever certain combinations of &Dn and &Qn are in effect. (Refer to "&Dn" command definition in this Chapter.) Cross Reference Commands - &Mn, &Qn S-registers - S7 DTE signals - DTR, DSR, CTS, RLSD, HS Line signals - Carrier LEDs - OH, CD, HS Relays - Auxiliary, Line, Phone Answering process Handshaking process +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Bn - Communications Options ----------------------------------------------------------------------------------------------------------------------------- Command AT [cmds] B[suffix] [cmds] Line Format Suffix Values See list below Factory Default See feature table Stored by &Wn yes Displayed by &V yes Description This command allows simultaneous selection of more than one n suffix; however, there are groups of n values and only the last n chosen from a group is in effect within that group. The B command is used to select the communication standard for data calls. The value of suffix n defines the desired communications standard setting at a particular modem line speed. B Command The Hayes OPTIMA and ACCURA products support the following B commands. B0 - CCITT V.22 when line speed is 1200 bit/second. B1 - Industry Standard 212A when line speed is 1200 bit/second. B2 - V.23 originate: T75/R1200 when DTE speed is 1200 bit/second. - V.23 answer: T75/R1200 when DTE speed is 1200 bit/second. B3 - V.23 originate: T1200/R75 when DTE speed is 1200 bit/second. - V.23 answer: T1200/R75 when DTE speed is 1200 bit/second. B6 - V.26 bis when line speed is 1200 bit/second. (HDX) B15 - V.21 when line speed is 300 bit/second. B16 - Industry Standard 103 when line speed is 300 bit/second. B30 - V.22 bis when line speed is 2400 bit/second. B32 - V.26 bis when line speed is 2400 bit/second. (HDX) B41 - V.32 when line speed is 4800 bit/second. B52 - V.32 bis when line speed is 7200 bit/second. B60 - V.32 when line speed is 9600 bit/second. B64 - V.FC when line speed is 9600 bit/second. B70 - V.32 bis when handshake begins at 12000 bit/second. B71 - V.FC when handshake begins at 12000 bit/second. B75 - V.32 bis when handshake begins at 14400 bit/second. B76 - V.FC when handshake begins at 14400 bit/second. B81 - V.FC when handshake begins at 16800-28800 bit/second. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ D - Dial Command ----------------------------------------------------------------------------------------------------------------------------- Command Line Format AT [cmds] D [Digits and Modifiers] [ ; [cmds] ] Factory Default N/A Stored by &Wn N/A Displayed by &V N/A Description Instructs the modem to execute the Dialing Process (i.e., go off hook and process the dial string), which may lead to executing the Handshaking Process. The dial string is a combination of dial digits and dial modifiers. If the modem is off hook, it neither initially waits nor attempts to detect dial tone before proceeding. The D command is not valid in the Online Command State or if either &Q2 or &Q3 is in effect. The D command may only be followed by dial digits and modifiers (if any), except for when the ; is used: in this case, the ; (semicolon) may only be followed by commands (if any). Invalid dial modifiers in the dial string (e.g., "-") are ignored. Refer to "Dialing Process and the Handshaking Process" in Chapter 8. The Dial Digits are: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, #, and *. Only the S=n dial modifier has any suffixes. These are displayed by the &V command only when they are a part of a stored number (refer to the &Zn= command) except for P and T, which are also commands. None of these may be stored by &Wn command except for P and T. P - Select Pulse Dialing - This dial modifier instructs the modem to use pulse dialing. Dialed digits are pulse-dialed in subsequent digits of the current dial string and in all future dial strings until a T command or dial modifier is executed. R - Originate Call In Answer Mode - This modifier instructs the modem to go into the answer mode rather than the originate mode after executing the dial string and starting the handshake. The same result occurs if several R dial modifiers are in the same dial string. S=n - Dial Stored Telephone Number - Indicates to the D command that the telephone dial string n, one of four such strings that may have previously been stored by an &Zn= command, is processed now. Syntax AT [cmds] D [dial-string] S[0|=n] [ignore] where: a. Other commands may precede the D command. b. Non-stored dial string characters after the D may precede the S. c. The S may be followed by 0 or =n, where n is 0-3. Invalid n causes an ERROR result code. If the character immediately following the S is not an = or a 0 then all characters after the S are ignored, and stored number 0 is dialed. T - Tone - The T dial modifier instructs the modem to send DTMF tones while dialing. Dialed digits are tone dialed until a P command or P dial modifier is selected. W - Wait For Dial Tone - If a valid dial tone is detected, the dial characters or modifiers following the command are executed. If dialtone is not detected before the specified time then the modem returns the NO DIALTONE result code and clears the call. If a busy signal is detected instead of dial tone, the modem returns the BUSY result code and clears the call, abandoning subsequent instructions in the dial string or on the command line. Comma (,) Pause - The comma dial modifier instructs the modem to pause for the amount of time specified by S8 (in seconds) before processing the next character in the dial string. This modifier is also used as a command. Quotes (") - Telephone numbers may be enclosed in double quote symbols ("). Enclosed characters may be digits or letters. Digits (0-9) are interpreted as numbers. Letters are interpreted as numbers according to the following table. Quote symbols are used in pairs; the first of a pair begins the quoted string, the second of a pair ends the quoted string. Subsequent quotes may be used; that is, several sections of a dial string may be individually enclosed in quotes. If a closing quote is not sent to the modem before the dial command is ended (by or ;), then the modem treats the dial string as if a closing quote occurred before the ending character. Letters Number Letters Number ----------------------------------------------------------------------------- ABC 2 MNO 6 DEF 3 PRS 7 GHI 4 TUV 8 JKL 5 WXY 9 Exclamation mark (!) - Flash - Flash is a dial modifier that is also known as hookflash, or register recall. It instructs the modem to go on-hook (for a time that is specific to the country) then return off-hook. The modem, if capable, lowers the off-hook resistance 100 +/- 10 ms before going on- hook for the flash and returns the off-hook resistance to normal 100 +/- 10 ms after the flash. This causes the flash duration to be 200 ms plus the length of the flash. @ - Wait For Quiet Answer - This dial modifier instructs the modem to look for line signal (ringback) followed by 6.5 +/- 0.5 seconds of silence (no detectable signal in call progress frequency band) up to the time specified in S7. If quiet answer is detected, the dial modifiers following the command are executed. If busy is detected, the modem returns a BUSY result code and goes to the hang-up process, aborting further execution of the dial string. Note: At least 6 seconds of silence is required to cover the ringing cadence of certain European countries. Note: Busy signal detection is enabled during execution of the W, @, and $ dial modifiers. Result Codes BUSY - if busy is detected (independent of Xn command selected). NO ANSWER - if quiet answer is not detected within time specified by S7. Note: NO ANSWER result code is used only by the @ dial modifier. $ - Wait for bong tone - The $ dial modifier invokes the following behavior. Note: Bong Tone is available on 28.8 kbits/second modems. 1. The modem waits for detection of the prompt tone as follows: a. If the modem does not detect the tone before the S7 timeout occurs, then the call is terminated, and the NO DIALTONE result code returned. b. If the modem detects the prompt tone before the time limit, then the modem pauses 1 second and executes the remainder of the dial string. 2. The prompt tone detector responds to tone 2 at any level between 0 dBm and -30 dBm if it lasts at least 200 ms. The tone detector does not respond to the following * tones outside the call progress band of 375 to 550 Hz, * tones whose duration is less than 200 ms, * tones (such as busy tone) that go off and back on in less than 1 second. Note: The Bellcore definition of the prompt tone is as follows: Tone 1 for 60 ms, followed immediately by Tone 2. Tone 1: 941 and 1477 Hz, constant level, two tones. Tone 2: 440 and 350 Hz, decaying with time constant of 200 ms, ending after 940 ms. The level of tone 1 is -10 dBm/freq. The initial level of tone 2 is -10dBm/freq. at-3TLP. Suggested method of detecting bong tone: 1. Measure the initial tone level, using a 50 ms observation interval. 2. Check the level again after 230 ms, again with a 50-ms observation interval. 3. Detect bong tone if the second level is 7 to 13 dB less than the first level, otherwise reject. Semicolon (;) - Return To Idle State - This dial modifier instructs the modem to return to the idle state and wait for more commands even though it has executed a dial command. The modem does not proceed to the Handshaking Process until an A or O or another D command is processed. The semicolon dial modifier may be part of a stored telephone number and is executed by the dialing process regardless of how the dialing process is entered. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ En - Select Command Character Echo Option ------------------------------------------------------------------------- Command Line Format AT [cmds] E [suffix] [cmds] Suffix Values 0 through 1 Factory Default E1 Stored by &Wn yes Displayed by &V yes Description This command instructs the modem to echo or not echo commands from the DTE. E0 - Off-line character echo disabled E1 - Off-line character echo enabled Execution Time 1 ms maximum Cross Reference DTE signals - RD LEDs - RD +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Hn - Control The Switchhook ----------------------------------------------------------------------------------------------------------------------------- Command Line Format AT [cmds] H [suffix] [cmds] Suffix Values 0 through 1 Factory Default N/A Stored by &Wn N/A Displayed by &V N/A Description The H command provides control over the line relay, and it can cause a transition to the hangup process. H0 instructs the modem to execute the hangup process if it is in one of following: * Online Command State, * Local Analog Loopback Self-test State * Online Command Substate of the Local Analog Loopback Process. If the modem is online and data transfer is still pending, then the modem stays connected for the time set by S38 in an attempt to complete the transfer of these data. If the data is sent before the time limit, the modem hangs up and returns the OK result code. If the data is not sent before the time limit, the modem hangs up and returns the NO CARRIER result code. See the S38 section in Chapter 6 for more details. H1 instructs the modem to go off-hook, but does not cause execution of the Handshaking Process. If the modem is already in the Online Command State, then H1 has no effect. H2 causes operation of the line relay but not the phone relay. This feature is used in some 1200 bit/second modems. Execution Time H0 - Depends on the modulation in use. 500 ms maximum, in async and sync Modes that do not use echo cancellation. Four seconds if modulation uses echo cancellation. See Chapter 8. The time is determined by S38 (def=20s) in buffered modes. H1: 10 ms maximum DTE Interface Lines Affected DSR, RL, SD, HS LEDs Affected CD, HS, MR, OH Cross Reference Commands - Ln, Mn, &Dn, &J, &Tn Line signals - Carrier, Ringing voltage Relays - Auxiliary, Line +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ I0 - Identify The Product Code ------------------------------------------------------------------------- Command Line Format AT [cmds] I [0] [cmds] Suffix Values 0 Factory Default N/A Stored by &Wn N/A Displayed by &V N/A Description I0 is used to report the highest line speed supported by the modem according to the following table. Highest line speed I0 response (bit/second) ------------------------------------------------------ 2400 249 9600 960 above 9600 actual speed in bits/second At all supported line speeds above 9600 bits/second, the I0 command reports the actual highest supported line speed in bits/second. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ I2 - Perform ROM Checksum Test ----------------------------------------------------------------------------------------------------------------------------- Command Line Format AT [cmds] I2 [cmds] Suffix Values N/A Factory Default N/A Stored by &Wn N/A Displayed by &V N/A Description I2 instructs the modem to verify the ROM checksums. Depending on whether the ROM checksums are determined to be correct, the modem produces an info-text that resembles a verbose result code. The actual result code associated with this command is OK. When the checksum is found to be valid, the info-text produced is as follows: OK where the associated and characters follow the rules defined for info-text messages in Chapter 3. Thus, when V0 is in effect, and the ROM checksum ID verified, the modem response to the ATI2 command line is as follows: OK0 where the and characters are controlled by registers S3 and S4, respectively. When the ROM checksum fails, the modem responds by issuing the following info-text: ERROR where the associated and characters follow the rules defined for info-text messages in Chapter 3. Thus, V1 is in effect, and the ROM checksum is invalid, the response to the ATI2 command line is as follows: ERROROK where the and are controlled, as usual, by registers S3 and S4, respectively. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ I7 - Version Number ----------------------------------------------------------------------------------------------------------------------------- Description The I7 command invokes the following info-text. Note: The I7 command is not supported in all OPTIMA and ACCURA products. This is the abbreviated name and speed that is used on the label. A maximum of 12 characters is allowed for the name. Example: VSM9600. This is the 4-character model number of the product. Example: 0123. This is the two-character country code of the country for which the modem is intended. Example: US. This is the version control number of the product. The format of is xx.yy. The version consists of a maximum of 5 characters, left justified. Example: 1.12. Copyright The copyright notice refers to the info-text invoked by the I7 command. The is 4 characters. Example: 1992. An example response to I7: SM09600, Model 0123US, Version 2.3 Copyright 1992 Hayes Microcomputer Products, Inc. Command Line Format AT [cmds] I7 [cmds] Suffix Values N/A Factory Default N/A Stored by &Wn N/A Displayed by &V N/A Reference VSET command +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Ln - Select Speaker Volume Level ----------------------------------------------------------------------------------------------------------------------------- Command Line Format AT [cmds] L [suffix] [cmds] Suffix Values 0 through 3 Factory Default L2 Stored by &Wn yes Displayed by &V yes Description This command determines the modem's speaker volume setting. L0 - Low speaker volume L1 - Low speaker volume L2 - Medium speaker volume L3 - High speaker volume The volume setting changes immediately and affects the sound output level if the speaker is enabled (see the Mn command), the modem is off hook, and a signal is present on tip and ring. Execution Time 100 ms maximum Cross Reference Commands - Mn +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Mn - Select Speaker Function Option ----------------------------------------------------------------------------------------------------------------------------- Command Line Format AT [cmds] M [suffix] [cmds] Suffix Values 0 through 4 Factory Default M1 Stored by &Wn yes Displayed by &V yes Description This command selects the speaker option. M0 - Speaker always off. M1 - Speaker on while off hook until carrier detected. M2 - Speaker always on while off hook; stays on after carrier is detected. M3 - Speaker off as digits are dialed, then on until carrier is detected. When dialing progress is reported, each digit or dial modifier character is sent to the DTE before the item is acted upon by the modem (within 20 ms before). For example, the first dialed digit would be sent to the DTE just before it is sent to the PSTN (Public Switched Telephone Network). A comma dial modifier is presented to the DTE at the beginning of the pause invoked by the comma. Dial tone is reported only if dial tone is actually detected. Dial tone is not reported if the X3 command is selected and dialing starts after a timed pause and not detection of dial tone. Silent answer is reported if the conditions for detection of silent answer are met, independent of whether or not the @ dial modifier was included in the dial string. If the S=n dial modifier is in the command sent to the modem, the modem presents the equivalent dial digits and modifiers to the DTE, not S=n. Even if the modem is already off hook, the speaker control is immediately updated by an Mn command. Execution Time 100 ms maximum Cross Reference Commands - Dn, Ln +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Nn - Select Negotiate Handshake Option ----------------------------------------------------------------------------------------------------------------------------- Command Line Format AT [cmds] N [suffix] [cmds] Suffix Values 0 through 5 Factory Default N1 Stored by &Wn yes Displayed by &V yes Description The N command selects whether or not the local modem performs a negotiated handshake with a remote modem when the communications speed of the two modems is different. Both symmetrical and asymmetrical handshake procedures can be selected. The choices for originate mode are as follows. Orig-A - Handshake only at the communication standard specified by S37 and Bn. Orig-B - Begin handshake at line speed specified by S37. Fallback to a lower speed is allowed. The modem listens for V.23 tone (1300 Hz) and 300- bit/second Frequency Shift Keying (FSK) carrier according to whether B15 (V.21) or B16 (Industry Standard 103) is selected. If one of the tones is detected, the originate modem attempts to connect to the detected modem type. See the "Handshake Procedures" section in Chapter 8. The choices for answer mode are as follows: Ans-A - Handshake only at the communication standard specified by S37 and Bn. Ans-B - Negotiate according to the following sequence of communication standards, starting at the highest speed allowed by the value of S37: V.FC, V.32 bis, V.32, V.22 bis, (V.22 or Industry Standard 212), V.21, and Industry Standard 103. V.22 versus Industry Standard 212 depends on the B command in effect. Ans-C - Negotiate according to the following sequence of communication standards, starting at the highest speed allowed by the value of S37: V.FC, V.32 bis, V.32, V.22 bis, (V.22 or Industry Standard 212), V.23, V.21, and Industry Standard 103. V.22 versus Industry Standard 212 depends on the B command in effect. Note: Ans-C is the same as Ans-B if V.23 modulation is not available. The following table associates the options with Nn commands. Option N0 N1 N2 N3 N4 N5 -------------------------------------------------- Orig-A X X X Orig-B X X X Ans-A X X Ans-B X X Ans-C X X +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ On - Go Online Command ------------------------------------------------------------------------- Command Line Format AT [cmds] O [suffix] Suffix Values 0, 1, 3 Factory Default N/A Stored by &Wn N/A Displayed by &V N/A Description If the modem is in the Online Command State, then the O0 command causes it to go to the online state of the previously established connection. If the O1 command is issued, then the modem goes to Online state and retrains its adaptive equalizer, if it has one. If the modem is off-hook in the idle state, then O0 and O1 cause it to go to the handshaking state. Originate or answer mode is determined from the last D or A command or R dial modifier that was selected. If the modem is on- hook in the Idle State, or if the modem is in a test state, then a command execution error results. O3 is valid only in the Online Command State and if rate re- negotiation is supported. The command tells the modem to initiate a rate re- negotiation procedure. The new rate possibilities are those selected by the value of S109, which must be set before issuing the O3 command. The value of S37 and N do not affect the rate re-negotiation procedure. If rate re-negotiation is not currently supported, then the modem returns ERROR to the O3 command. Result Codes ERROR - if modem is on hook or &T1, &T3, &T6-&T8 is active or On cannot be executed. CONNECT - if successfully returned to Online State NO CARRIER - if O1 is issued and the equalizer retrain is not successful in the time specified by S7. Execution Time Depends on retrain procedure (per modulation type). Cross Reference Commands - &T1, &T3, &T6-&T8 DTE signals - DTR, DSR, CTS, RLSD Line signals - Carrier LEDs - CD, HS +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ P - Select Pulse Dialing Method ------------------------------------------------------------------------- Command Line Format AT [cmds] P [cmds] Suffix Values none Factory Default P (as opposed to "T") Stored by &Wn yes Displayed by &V yes Description This command instructs the modem to use pulse dialing. Dialed digits are pulse dialed until a T command or dial modifier is received. Execution Time 1 ms maximum Cross Reference Commands - Dn, T, P dial modifier +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Qn - Select Result Code Option ----------------------------------------------------------------------------------------------------------------------------- Command Line Format AT [cmds] Q [suffix] [cmds] Suffix Values 0 through 2 Factory Default Q0 Stored by &Wn yes Displayed by &V yes Description Qn instructs the modem whether or not to give result codes to the DTE. Result Codes Q0 - Result codes enabled Q1 - Result codes disabled Q2 - Disables the RING result code. In answer mode, also disables CONNECT and NO CARRIER result codes. Execution Time 1 ms maximum Cross Reference DTE signals - RD LEDs - RD Result Codes Execution Time +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Sn= - Write To An S-Register ----------------------------------------------------------------------------------------------------------------------------- Command Line Format AT [cmds] [ S [ ]] = [cmds] Address Values Refer to Chapter 6 Data Values Refer to Chapter 6 Factory Default S0 Stored by &Wn no Displayed by &V N/A Description The command is issued as Sn=x. The value of x is written to the S- register specified by n, overriding the previous value. If no n suffix is present, the address 0 is used. If no x value is present, the value 0 is written. Example: ATS=x means S0=x AT=x means Sn=x, where n is the suffix of the last named S-register. Execution Time 5 ms maximum Cross Reference Commands - Sn, Sn? LEDs - AA, HS, TR +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Sn? - Read An S-Register ------------------------------------------------------------------------- Command Line Format AT [cmds] [ S [ ]] ? [cmds] Address Values 0 through 255 Factory Default S0 Stored by &Wn no Displayed by &V N/A Description The contents of S-register n are sent as three decimal digits. This info- text response is formatted with as determined by the Vn command currently in effect. If no n (suffix) is present, the last register selection is assumed. On power up, the default selection is 0. Note: ? is interpreted by the modem as Sn?. Cross Reference Commands - Sn, Sn= +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ T - Select Tone Dialing Method ----------------------------------------------------------------------------------------------------------------------------- Command Line Format AT [cmds] T [cmds] Suffix Values none Factory Default P (as opposed to "T") Stored by &Wn yes Displayed by &V yes Description The T command instructs the modem to send DTMF tones while dialing. Dialed digits are tone dialed until a P command or dial modifier is received. Execution Time 1 ms maximum Cross Reference Commands - Dn, P, T dial modifier +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Vn - Select Response Format Option ------------------------------------------------------------------------- Command Line Format AT [cmds] V [suffix] [cmds] Suffix Values 0 through 1 Factory Default V1 Stored by &Wn yes Displayed by &V yes Description The Vn command determines which format to use (i.e., verbose versus numeric) for info-text and result codes. Refer to the table below. Note that and are defined by S-registers S3 and S4, respectively. V0 - Result codes displayed in numeric form V1 - Result codes displayed in verbose form The following table shows the formats. See also the Q command. Note: The "text" of the info-text in the table below may consist of multiple lines of text. The formats depicted here only refer to the characters between info-texts and not within them. V0 V1 ---------------------------------------------------- Info-text text text Result codes numeric code verbose code Result Code Info-text Formats Execution Time 1 ms maximum Cross Reference Information Text Result Codes Execution Time +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Wn Select Extended Result Code ------------------------------------------------------------------------- Command Line Format AT [cmds] W [suffix] [cmds] Suffix Values 0 through 2 Factory Default W0 Stored by &Wn yes Displayed by &V yes Description The Wn command works in conjunction with register S95 to determine which result codes are used to describe the type of connection and protocol, etc., that resulted from handshaking and negotiation. Wn allows for extended result codes in addition to the CONNECT result code. When the modem is operated in error-control mode (&Q5 is in effect), Wn and S95 together allow you to select these additional Result Codes: * CARRIER * PROTOCOL * AUTOSTREAM * COMPRESSION * CONNECT. Any result codes which are enabled by Wn and S95 are produced in the order indicated above. Result codes that are not enabled by the Wn command may be turned-on by setting certain bits in S95. If AutoStream is not being used, then no AutoStream result code is returned. Also, if the connection results in PROTOCOL: NONE, then there is no COMPRESSION: result code. The S95 result code bit map, which has all zeros as the Factory Default value, overrides the characteristics of the Wn commands described below when any bit is set. W0- CONNECT result code reports DTE speed, and if S95=0 (default), then disable all extended connection result codes. W1- CONNECT result code reports DTE speed, and if S95=0 (default), then enable the CARRIER and PROTOCOL extended result codes. W2- CONNECT result code reports DCE speed, and if S95=0 (default), then disable all extended result codes. Refer to the bit map presented with the S95 definition in Chapter 6. Notes: 1) Selecting W0 and setting S95=12 (decimal) is the same as selecting W1; and that selecting W0 and setting S95=1 (decimal) is the same as selecting W2. 2) There is no setting of S95 that forces W2 to report DTE speed in the CONNECT result code; and that there is no setting of S95 that forces W1 to not produce the CARRIER and PROTOCOL result codes. The use of S95 represents an extension of the function that the Wn command was intended to perform. The version of the Wn command here with S95=0 (default) maintains backwards compatibility with previous V-Series products. However, selecting W0 and setting S95 as required permits you to tailor result codes characteristics to their own requirements in a compatible way. Refer to Chapter 5 for more information. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Xn Select Call Progress Option ------------------------------------------------------------------------- Command Line Format AT [cmds] X [suffix] [cmds] Suffix Values 0 through 4 Factory Default X4 Stored by &Wn yes Displayed by &V yes Description This command enables tone detection options and the associated result codes. Result codes definitions are covered in Chapter 8. X0 - Busy and dial tone detect disabled. Result codes 0-4 enabled. Only CONNECT result code allowed, and not the CONNECT XXXX result code. Overrides Wn and S95. X1 - Busy and dial tone detect disabled. Result codes 0-5, all CONNECT XXXX, Wn and S95 enabled. X2 - Busy detect disabled. Dial tone detect enabled. Result codes 0-6, all CONNECT XXXX, Wn and S95 enabled. X3 - Busy detect enabled. Dial tone detect disabled. Result codes 0-5, 7, all CONNECT XXXX, Wn and S95 enabled. X4 - Busy and dial tone detect enabled. Result codes 0-7, all CONNECT XXXX, Wn and S95 enabled. Note: The @ and W dial modifier result codes are not affected by the Xn command in effect. The @ dial modifier enables result codes 8 (NO ANSWER) and 7 (BUSY) each time it occurs in the dial string. The W dial modifier enables result codes 6 (NO DIALTONE) and 7 (BUSY) each time it occurs in the dial string. Execution Time 1 ms maximum Cross Reference Commands - A, Dn, O, W S-registers - S6, S7 Line signals - Busy, Dial tone, Carrier +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Yn Select Long Space Disconnect Option ------------------------------------------------------------------------- Command Line Format AT [cmds] Y[suffix] [cmds] Suffix Values 0, 1 Factory Default Y0 Stored by &Wn yes Displayed by &V yes Description The Y command determines if the modem disconnects a call upon receiving a long space (1.6 sec break) signal from the distant end. If Y1 is selected, the modem sends a 4-second break (space) before going on hook when an H0 command is issued or, if &D2 is selected, when DTR goes off. Y0 - Disable long space disconnect Y1 - Enable long space disconnect Note: Y1 is only supported when the modem is using &Q0 or &Q6 Async communication modes. Long-space disconnect is not supported in any of the error-control modes. Execution Time 1 ms maximum Cross Reference Commands - Hn, &Dn Register - S82 Hang up process +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Zn Perform Soft Reset ----------------------------------------------------------------------------------------------------------------------------- Command Line Format AT [cmds] Z [suffix] Suffix Values 0 through 1 Factory Default N/A Stored by &Wn N/A Displayed by &V N/A Description This command tells the modem to go on hook and restore the selected stored profile. The modem does not execute any commands that follow the Zn command on the same command line. Z0 - Recall stored profile 0 Z1 - Recall stored profile 1 Refer to the &Wn command for description of which modem parameters are included in a stored profile. Execution Time 2 seconds maximum DTE Interface Lines Affected DSR, RLSD LEDs Affected AA, CD, MR, OH, TR Cross Reference Commands - &Wn DTE signals - RI Straps - Dumb Relays - Auxiliary, Line, Phone +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ &An - Select Originate/Answer Role For Autoanswer ------------------------------------------------------------------------- Command Line Format AT [cmds] &A [suffix] [cmds] Suffix Values 0 through 1 Factory Default &A0 Stored by &Wn yes Displayed by &V yes Description This command determines whether the modem attempts to connect as the Originating or Answering modem when Autoanswering calls. It may be useful in call-back security techniques. &A or &A0 - Use Answer direction when Autoanswering. &A1 - Use Originate direction when Autoanswering. Execution Time 2 ms maximum DTE Interface Lines Affected None LEDs Affected None Cross Reference Commands: A, D, S-0 DTE Signals: RI Straps: NONE Relays: NONE Process: Answer, Handshake +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ &Cn - Select Data Carrier Detect Option ------------------------------------------------------------------------- Command Line Format AT [cmds] &C [suffix] [cmds] Suffix Values 0 through 2 Factory Default &C0 Stored by &Wn yes Displayed by &V yes Description This command determines how the state of the RLSD lead relates to the carrier from the distant end. The command takes effect immediately in both the Idle State and the Online Command State. The behavior patterns for RLSD depend on the specific &Cn and &Qn commands in effect. Also, RLSD patterns depend on whether online operation is half- or full-duplex. Finally, if &Q5 is in effect, RLSD behavior depends on whether S10=255 or S10<255. Refer to the tables below. Legend Behaviors in the Tables -------------------------------------------------------------------------- A The RLSD circuit is ON at all times. B The RLSD circuit is OFF in the Idle State, goes ON immediately after the CONNECT result code is issued, and goes OFF immediately after loss of carrier. If carrier goes on and stays on for the time set by S9, then RLSD goes ON again. C RLSD is OFF in Idle, tracks carrier in Online State. The RLSD circuit is OFF in the Idle State. It goes ON immediately after the CONNECT result code is issued, and goes OFF immediately after loss of remote carrier. If the remote carrier is restored, then RLSD goes ON (without the S9 delay). D RLSD is ON in Idle, RLSD tracks in Online. The RLSD circuit is normally ON in the Idle State, and it is ON while the remote carrier is present in the online State. In the online state, RLSD goes OFF immediately after loss of carrier. If carrier goes ON and stays on for the time set by S9, then RLSD goes ON again. If the hangup process begins while RLSD is OFF, then RLSD goes ON just prior to the issue of the NO CARRIER result code. E RLSD is OFF in Idle, ON in Online State. The RLSD circuit is OFF in the Idle State. It goes ON immediately after the CONNECT result code is issued, and it goes OFF when the modem begins the Hangup Process. RLSD does not track the presence of carrier. F RLSD is ON in Idle and tracks carrier in Online states, without S9 delay. RLSD Behaviors for Full Duplex Operation Command &C0 &C1 &C2 -------------------------------------- &Q0 A B D &Q1 B B B &Q2 B B B &Q3 B B B &Q4 B B B &Q5 A E A &Q6 A B D &Q5 S10=255 A B D The RLSD circuit is normally ON in the Idle State, and it is ON while the remote carrier is present in the Online State. It goes OFF approximately 3 seconds after loss of remote carrier. If the remote carrier is restored, then RLSD goes ON again (regardless of S9). If the Hangup Process is initiated by the DTE using DTR or issuing ATH from the Online Command State, then RLSD returns ON just prior to the modem issuing the OK result code. The modem does not begin the Hangup Process if S10=255. Execution Time Maximum 1 ms DTE Interface Lines Affected RLSD Cross Reference Commands - &Mn, &Qn DTE signals - RLSD Line signals - Carrier LEDs - CD Processes - Hang-up S-registers - S9, S10 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ &Dn Select Data Terminal Ready Option ------------------------------------------------------------------------- Command Line Format AT [cmds] &D [suffix] [cmds] Suffix Values 0 through 3 Factory Default &D0 Stored by &Wn yes Displayed by &V yes Description The &Dn command affects how the modem responds to the state of DTR and changes of DTR. The effects of DTR states and changes are also dependent upon the current communication mode (&Qn or &Mn command). The test modes associated with certain &Tn commands are only affected by DTR changes when &D3 is in effect and are not affected by &Qn or &Mn commands. The TR LED shows the state of DTR except when &D0 and &Q0 are in effect. Note that TR may have special uses in certain test modes. The following sections describe what DTR does for each mode of modem operation. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Dumb, switched The following chart describes what DTR does for Dumb switched mode of operation. Note: This feature is available in OPTIMA products. &D0 &D1 &D2 &D3 ------------------------------------------------------------------------- V.14 (&Q0) none none I, H R &Q1 C, H C I, C, H C, R &Q2 I, D, H I, D, H I, D, H I, D, R &Q3 I, O, H I, O, H I, O, H I, O, R AutoSync H none I, H R AutoSync II none none I, H R error control none none I, S R ASB none none I, S R +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Smart AT, switched The following chart describes what DTR does for smart AT switched mode of operation. &D0 &D1 &D2 &D3 ------------------------------------------------------------------------- V.14 (&Q0) none E I, H R &Q1 C, H C, E I, C, H C, R &Q2 I, D, H I, D, H I, D, H I, D, R &Q3 I, O, H I, O, H I, O, H I, O, R AutoSync H E I, H R AutoSync II none E I, H R error control none E I, S R ASB none E I, S R +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Timing of DTR Off-To-On Transitions The off-to-on transition of the DTR lead function may initiate certain functions as described below. The process initiated by the DTR off-to-on transition is started no sooner than 5 ms and no later than 50 ms of the DTR transition. S25 does not affect DTR off-to-on timing under any conditions. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Timing of DTR On-To-Off Transitions If the modem is on line, when a DTR on-to-off transition occurs, it must last at least the time indicated by the value of S25 in order to be valid; shorter durations are ignored by the modem. Thus, the processes indicated above are started no sooner than the time indicated by the S25 register; and no later than 50 ms longer than the time in S25. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ DTR-Initiated Hard Reset (&D3 in effect) When &D3 is in effect, the modem begins a hard reset process within 1 ms of the DTR on-to-off event regardless of the modems current state and regardless of the &Qn command in effect. S25 does not affect DTR on-to-off timing when &D3 is in effect. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ &F - Load Factory Default Profile ----------------------------------------------------------------------------------------------------------------------------- Command Line Format AT [cmds] &F [cmds] Suffix Values none Factory Default N/A Stored by &Wn N/A Displayed by &V N/A Description This command tells the modem to copy the Factory Default commands and S-register values into the active profile. See the individual command and register descriptions for default values. The &F command is not valid in the Online Command State. Execution Time 1.5 seconds max (this time needed for some new technologies). Cross Reference LEDs - TR +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ &Gn - Select Guard Tone Option ----------------------------------------------------------------------------------------------------------------------------- Command Line Format AT [cmds] &G [suffix] [cmds] Suffix Values 0, 2 Factory Default &G0 Stored by &Wn yes Displayed by &V yes Description This command tells the modem which guard tone, if any, to transmit while transmitting in the high band (answer mode). &G0 - Guard tones disabled. &G2 - 1800 Hz guard tone enabled. (V.22, V.22 bis only). Note: Guard tone is transmitted only while the modem is in the transmitting in the answer mode and during the answer handshake. Cross Reference Commands - A Line signals - Guard tone Answer process +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ &Kn - Select Flow Control Option ------------------------------------------------------------------------- Command Line Format AT [cmds] &Kn [cmds] Suffix Values 0-6 Factory Default &K3 Stored by &Wn yes Displayed by &V yes Description If the parameter +FCLASS equals 0 or the modem does not have any other +FCLASS values, the &Kn command is used to select the local flow control method. Local flow control is used only when Online in a buffered mode (i.e., error-control or buffered asynchronous). Flow control is always inhibited in command state. Flow control regulates the data stream between the DTE and modem's DTE interface. Specific functions depending on suffix value are as follows: Command Meaning ------------------------------------------------- &K0 Disable all flow control. May be selected for use during buffered mode at the risk of overflowing the buffers and losing data. &K1 not used &K2 not used &K3 Enable bidirectional hardware flow control. Note that the DTE-to-modem cable must have the RTS/CTS wires. The &T19 command may be used by software to determine if the cable is properly wired. &K4 Enable bidirectional XON/XOFF flow control. These characters are not programmable and are fixed at DC1 and DC3, respectively. This method should not be used when XON/XOFF characters are sent as user data or as part of a file transfer protocol. &K5 Enable Transparent XON/XOFF flow control. See detailed description below. &K6 Enable Unidirectional XON/XOFF flow control. DC1 and DC3 characters are sent to the DTE by the modem. DC1 and DC3 from the DTE to the modem are treated as user data and transmitted to the remote modem. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Transparent flow control Transparent Flow Control provides a method of local flow control over any DTE-DCE link which can pass an 8-bit data stream intact. The method works by cloaking user data which might otherwise be interpreted as Xon/Xoff by the DCE or DTE. The cloaked user data passes across the local DTE-DCE connection and is then uncloaked and sent on in it's original form. The cloaking process inserts an escape character and then the user data character which has been XOR'd with $21. Decloaking detects (and removes) the escape character and XOR's the next character with $21 to restore the original user data. Characters $10, $11, $13, $90, $91, and $93 are processed in this way. The modem assumes the Xon state (Tx and Rx channels) when entering data mode. The modem interprets $13 or $93 from the DTE as Flow-Off, and $11 or $91 as Flow-On. The modem uncloaks character pairs from the DTE that start with $10 or $90, and sends the uncloaked versions to the distant end. Cloaked = $10 or $90 followed by $31, $30, $32, $B1, $B0, or $B2. Uncloaked = $10, $11, $13, $90, $91, or $93. The modem cloaks incoming data (data received from the line) as indicated in the following table, according to the character format of the last AT command. Character Format Received Data 7S1 7M1 7E1 7O1 ------------------------------------------------------------------------------------------------------------- $10 becomes $10$31 $90$31 $90$31 $10$31 $11 $10$30 $90$30 $90$30 $10$30 $13 $10$32 $90$32 $90$32 $10$32 $90 $10$B1 $90$B1 $90$B1 $10$B1 $91 $10$B0 $90$B0 $90$B0 $10$B0 $93 $10$B2 $90$B2 $90$B2 $10$B2 When it enters the data mode the modem assumes Xon state; that is, the modem is free to send data to the DTE. If transmit buffer goes above it's high water mark, then send Xoff. If transmit buffer goes below it's low water mark, then send Xon. The modem sends the following characters as Xon and Xoff to the DTE, according to the character format of the last AT command. Character Format Received Data 7S1 7M1 7E1 7O1 ----------------------------------------------------------------------- Xon = $11 $91 $11 $91 Xoff = $13 $93 $13 $93 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ &Pn - Select Pulse Dialing Parameters -------------------------------------------------------------------------- Command Line Format AT [cmds] &P [suffix] [cmds] Suffix Values 0, 1 Factory Default N/A Stored by &Wn yes Displayed by &V no Description The &Pn commands select the pulse dialing parameters. * &P0 - Normal (US) digit encoding and make/break times. The digit encoding and times associated with the &P1 and &P2 commands are country specific. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ &Qn - Select Communications Mode Option ------------------------------------------------------------------------- Command Line Format AT [cmds] &Q [suffix] [cmds] Suffix Values 0-6, 8-10 Factory Default &Q5 Stored by &Wn yes Displayed by &V yes Description The &Q command selects the communication mode and is the extended version of the &M command. The &Q command determines how the modem treats transmitted and received data while in the Online state (i.e., asynchronous, synchronous, AutoSync, error-control, or buffered asynchronous) and establishes certain call setup procedures. Refer also to the &Cn, &Dn, and &Sn commands in this chapter, and to the "Dialing, Answer, and Hangup Processes" in Chapter 8. The &Q2 and &Q3 commands are intended to enable use of the modem by synchronous terminals. The modem is configured by an asynchronous DTE, while DTR is off. Then the synchronous terminal is connected to the modem and calls are controlled by DTR as described below. If the value of S0 is not 0, and ringing is detected, then after DTR goes on the modem answers the call when the following conditions are satisfied: (1) after the next ring and (2) when the value of S1 equals or exceeds that of S0. Note: Detection of ringing is forgotten by the modem if ringing is not detected for 8 seconds. Because of the intended use by synchronous terminals, the A (answer) and D (dial) commands are invalid when either &Q2 or &Q3 is selected. The modem sends the ERROR result code if it receives an A or D command (which would have to occur while DTR is off). All of the &Qn commands are valid in the off-line command state; none are valid in the Online Command State (return ERROR). Command Online State Special Features (see NOTE below.) --------------------------------------------------------------------------- &Q0 Asynchronous RLSD, DSR, and DTR behaviors are unique. (Refer to &Cn, &Sn and &Dn command definitions). &Q1 Synchronous In smart and switched dumb mode, DTR must be ON after CONNECT when a timer equal to S25 expires. DTR is ignored in dumb leased-line mode. Available in OPTIMA products. &Q2 Synchronous DTR OFF-to-ON executes Dialing Process; D command invalid. DTR is ignored in dumb leased-line mode. Available in OPTIMA products. DTR ON-to-OFF executes Hangup Process (or the Reset Process if &D3 is in effect). The A command is invalid. Available in OPTIMA products. &Q3 Synchronous Dialing and Voice allowed from telephone when DTR is OFF. DTR is ignored in dumb leased-line mode. DTR OFF-to-ON executes the Handshaking Process (in orig); the D command is invalid. DTR ON-to-OFF executes Hangup Process (or the Reset Process if &D3 is in effect). The A command is invalid. Available in OPTIMA products. &Q4 Hayes AutoSync If AutoSync is in effect, DTR must be ON after CONNECT when check timer equal to S25 expires; AutoSync II does not wait S25 time to DTR. Refer to the &Dn command for other DTR behaviors in &Q4 mode and refer to the AutoSync and AutoSync II specifications for other details of how S25 affects modem operation. Available in 28.8 kbits/second OPTIMA products. &Q5 Error-Control This enables error-control. Depending upon various other commands, any one of several point-to-point protocols may be negotiated. After the modem handshake is complete, feature negotiation (see S48) is used to determine which protocol (see S46) is used for the communication session. If no common protocol is found between the local and remote modems, the fall back options (see S36) is used. These may include Automatic Speed Buffering (ASB), asynchronous mode or going on-hook. When in &Q5 mode, the DTE is always presented an asynchronous interface. When either error-control or ASB has been negotiated, flow control (&Kn) should not be disabled. The &Q1, &Q2, &Q3, and &Q4 commands return ERROR when issued while online during an error- control or ASB connection. &Q6 Buffered Automatic Speed Buffering is Asynchronous useful for DTEs which cannot adjust to changing transmission speeds. This mode ensures the DTE-modem speed is set at a constant rate regardless of the line speed determined during the modem handshake. With the exception of flow control (&Kn) between the DTE and the attached modem, this mode is identical to the standard asynchronous mode (&Q0). ASB operation is also a fall back option (see S36) when the modem is set for error-control mode (&Q5). This feature is available in 28.8 kbits/second OPTIMA modems. Because the DTE and DCE speeds are different in ASB, a 256-byte buffer is provided so that flow control does not occur on every character transmission. Some DTEs are sensitive to the buffer size so S-registers are provided to control the lower (S49) and upper (S50) boundaries. &Q8 MNP Error-Control The modem attempts to negotiate an MNP error-control link upon connection. The current setting in S46 bit 1 determines whether MNP (TM) 2-4 or MNP5 is negotiated. If S46 bit 1 is set to 1, MNP5 is preferred. If an MNP error-control protocol is not established, the modem falls- back according to the current setting in S36. If S36 bit 0 is 0 the modem hangs-up. If S36 bit 0 is 1 the modem connects according to S36 bit 1. If S36 bit 1 is 0 the modem connects in Direct Async mode. If S36 bit 1 is 1 the modem connects in Buffered Async mode. The settings in S48 and S46 (except bit 1) are ignored. If fallback to Buffered Async mode occurs, all data received during protocol negotiations are present in the received data buffer. The &Kn command setting determines the type of local flow-control while in error-control or buffered modes. &Q9 V.42bis/MNP2-4 The modem attempts to negotiate a V.42bis error-control link upon connection. If V.42bis (or V.42) is not achieved, then MNP2-4 is attempted. Error-Control If neither error-control protocol is established, the modem falls-back according to the current setting in S36. If S36 bit 0 is 0 the modem hangs-up. If S36 bit 0 is 1 the modem connects according to S36 bit 1. If S36 bit 1 is 0 the modem connects in Direct Async mode. If S36 bit 1 is 1 the modem connects in Buffered Async mode. The settings in S48 and S46 are ignored. If fall-back to Buffered Async mode occurs, all data received during protocol negotiations is present in the received data buffer. &Kn determines the type of local flow-control while in error-control or buffered modes. Note: Refer to &Cn, &Sn, and &Dn, in this chapter, and to the Handshaking, Dialing, and Answering Processes in Chapter 8 for additional information on interface lead behaviors. Note: Refer to the &Kn and &Nn commands, to S36, S37, S46, S48, and to Chapter 8 for additional information on &Q5 and &Q6 operation. DTE Interface Lines Affected DSR, RLSD Cross Reference Commands - &Cn, &Dn, &Mn, &Sn, &Kn, Nn S-registers - S36 Negotiation Fall Back S37 Desired DCE Line Speed S46 Protocol Selection S48 Feature Negotiation Action S49 ASB Buffer: Low Boundary S50 ASB Buffer: High Boundary DTE signals - DSR, DTR, RLSD LEDs - TR +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ &Rn - Select RTS/CTS Option ------------------------------------------------------------------------- Command Line Format AT [cmds] &R [suffix] [cmds] Suffix Values 0 through 1 Factory Default &R0 Stored by &Wn yes Displayed by &V yes Description The functions of Clear to Send (CTS) in synchronous modes (&Q1, &Q2, and &Q3) are determined by the &R command. The &Rn command has no effect when the DTE Interface is asynchronous. See also CTS and RTS in Chapter 11. Refer to the &Kn command for other RTS and CTS functions. Note: This feature is available in OPTIMA products. Note: When &Q4 is in effect (AutoSync operation), RTS and CTS behaviors are unique. In Synchronous Modes (&Q1, &Q2, and &Q3): &R0 - CTS tracks RTS while the modem is in Online State and observes the RTS-to-CTS delay determined by S26. &R1 - CTS is ON while the modem is in the Online State, and RTS is ignored. DTE Interface Lines Affected CTS Cross Reference Commands - &Mn, &Qn S-registers - S26 DTE signals - RTS, CTS +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ &Sn - Select Data Set Ready Option ----------------------------------------------------------------------------------------------------------------------------- Command Line Format AT [cmds] &S [suffix] [cmds] Suffix Values 0 through 2 Factory Default &S0 Stored by &Wn yes Displayed by &V yes Description The functions of DSR are determined by the &Sn command in effect. When &Q0, &Q5, and &Q6 are in effect: &S0 - DSR circuit is always on. &S1 - DSR is off in the Idle State and when in a test mode. DSR circuit is turned ON at start of the Handshaking Process. DSR is turned OFF when Hangup Process is started. &S2 - DSR is off in the Idle State and when in a test mode. DSR circuit is turned ON at end of handshake prior to issuing of the CONNECT result code. DSR is turned OFF when Hangup Process is started. When &Q1 to &Q4 are in effect: &S0-1 - DSR is off in the Idle State. DSR circuit is turned ON at start of the Handshaking Process. DSR is turned OFF when Hangup Process is started. &S2 - DSR is off in the Idle State. DSR circuit is turned ON at end of handshake prior to issuing of the CONNECT result code. DSR is turned OFF when Hangup Process is started. DTE Interface Lines Affected DSR Cross Reference Commands - &Mn, &Qn DTE signals - DSR Line signals - Answer tone +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ &T0 - Terminate Test In Process ----------------------------------------------------------------------------------------------------------------------------- Command Line Format AT [cmds] &T0 Factory Default N/A Stored by &Wn N/A Displayed by &V N/A Description If a test is in process as a result of executing an &Tn command, then the &T0 command causes that test to be terminated. See specific &Tn descriptions for termination actions. If no test is in progress when the &T0 command is sent to the modem, the modem takes no action except to return the OK result code. Execution Time 2 ms maximum LEDs Affected MR Cross Reference Commands - &T1, &T3, &T6-&T8 S-registers - S18 DTE signals - DSR +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ &T1 - Initiate Local Analog Loopback ----------------------------------------------------------------------------------------------------------------------------- Command Line Format AT [cmds] &T1 [suffix] Suffix Values O or A Factory Default N/A Stored by &Wn N/A Displayed by &V N/A Description The modem goes on hook and configures itself for analog loopback (using low frequency band if no suffix or O suffix, and high frequency band if A suffix). DSR is turned off (if &S1 is in effect), the analog loopback state is entered, and the test timer is set to the value in S18. A CONNECT result code is sent to the DTE, and the test timer then begins its count down. The test terminates when the test timer expires. If S18 equals 0, then the test can only be terminated by escaping from the online state into the Online Command State and sending an &T0, H0, or Zn command; or by a DTR on-to- off transition under certain conditions. Refer to Chapter 8. While any command may be entered while the modem is in this test state, the modem response is not specified except for H0, &T0, and Zn, any of which terminates the test. Upon termination of the test, the modem reverts to the Idle State. The command is only valid in the Idle State. Result Codes CONNECT - when local analog loopback state is entered. OK - after test is stopped by either the test timer, the H0 command, or the &T0 command. ERROR - if any other &Tn test is active (except &T0) or if in the Online Command State. Execution Time Determined by test timer or until aborted by a command. DTE Interface Lines Affected DSR LEDs Affected MR flashes Cross Reference Commands - &Sn, &T0, &T8, H0, Zn S-registers - S18 DTE signals - DSR +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ &T3 - Perform Local Digital Loopback ----------------------------------------------------------------------------------------------------------------------------- Command Line Format AT [cmds] &T3 [cmds] Suffix Values N/A Factory Default N/A Stored by &Wn N/A Displayed by &V N/A Description The modem must be in the Online Command State when this command is issued. Otherwise an ERROR result code occurs. This command establishes a loopback of received data, after demodulation, and sends it back to the distant end. The modem is configured for local digital loopback, DSR is turned off (if &S1 is in effect), with the test timer is started with the value in S18, and an OK result code is sent to the DTE. If S18 contains a 0, the test must be terminated by a &T0, H0, or Zn command. The latter two result in the modem going on hook. If S18 does not contain 0, the test is terminated after the number of seconds stored in S18. The MR light flashes while the test is in progress. Result Codes OK - after 2 s delay ERROR - if any other self test is active (&T1, &T6-&T8) or if in Idle State. OK - when test is terminated. Execution Time Determined by test timer or until aborted by a command. DTE Interface Lines Affected DSR LEDs Affected MR flashes Cross Reference Commands - &Sn, &T0, H0, Zn S-registers - S18 DTE signals - DSR +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ &T4 - Enable Granting Of RDL Requests ----------------------------------------------------------------------------------------------------------------------------- Command Line Format AT [cmds] &T4 [cmds] Suffix Values N/A Factory Default &T4 (as opposed to &T5) Stored by &Wn yes Displayed by &V yes Description When in the Online State the modem honors a remote digital loopback request from a distant modem if it occurs. This results in an ERROR if the command is given while any test is active (&T1, &T3, &T6, &T7, or &T8). Cross Reference Commands - &T5 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ &T5 - Deny Granting Of RDL Requests ----------------------------------------------------------------------------------------------------------------------------- Command Line Format AT [cmds] &T5 [cmds] Suffix Values N/A Factory Default &T4 (as opposed to &T5) Stored by &Wn yes Displayed by &V yes Description The modem does not respond to a remote digital loopback request from a distant modem. This command is not valid if given while any test is active (&T1, &T3, &T6, &T7, or &T8). Cross Reference Commands - &T4 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ &T6 - Initiate Remote Digital Loopback ----------------------------------------------------------------------------------------------------------------------------- Command Line Format AT [cmds] &T6 Suffix Values N/A Factory Default N/A Stored by &Wn N/A Displayed by &V N/A Description The command is only valid if the modem is in the Online Command State, the modulation is one of the Quadrature Amplitude Modulation (QAM) types that support full-duplex transmission, and the speed is the same in both directions. The command is not valid for any FSK modulation (e.g., V.21 and V.23). Recommendations V.22 and V.22 bis specify how remote digital loopback is initiated and ended for V.22 and V.22 bis modems. Recommendation V.54 specifies how the loopback is initiated and ended on other types of full-duplex modems. The modem sends the remote digital loopback request signal to the distant modem. After the RDL acknowledgment signal is received from the distant modem, DSR is turned off (if &S1 is in effect), the Online State is entered, a CONNECT result code is sent to the DTE, and the test timer is set to the value in S18. If the modem does not receive the RDL acknowledgment signal from the distant end in 3 seconds, it sends an ERROR result code to the DTE and returns to the Online Command State. The modem sends the signal to release the remote digital loopback when the test is terminated. The test may be terminated by the H0, Zn, or &T0 command. The test also terminates when the test timer expires (sending the modem to the Online Command State) or carrier is lost (causing a NO CARRIER result code and the modem to go on hook in the Idle State). Result Codes CONNECT - when Online State is entered. ERROR - if any test is active (&T1, &T3, &T6-&T8). ERROR - if not in Online Command State. ERROR - if command is invalid ERROR - if the RDL signal is not acknowledged. Execution Time Command execution lasts for the time it takes to receive the RDL acknowledgment signal plus the test time. DTE Interface Lines Affected DSR LEDs Affected MR flashes Cross Reference Commands - &Sn, &T0, &T7, Hn, Zn S-registers - S18 DTE signals - DSR +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ &T7 - Initiate RDL With Self Test ----------------------------------------------------------------------------------------------------------------------------- Command Line Format AT [cmds] &T7 Suffix Values N/A Factory Default N/A Stored by &Wn N/A Displayed by &V N/A Description The command is only valid if the modem is in the Online Command State, the modulation is one of the QAM types that support full- duplex transmission, and the speed is the same in both directions. The command is not valid for any FSK modulation (e.g., V.21 and V.23). The modem sends the remote digital loopback request signal to the distant end. After the RDL acknowledgment signal is received from the distant end, DSR is turned off (if &S1 is in effect), the Online State is entered, an OK result code is sent to the DTE, and the test timer is set to the value in S18. While the test is active the modem sends a test message to the distant end and counts the errors in the received (looped back) signal. The modem stays in the Online Command State during the test. When the test is terminated (except by a loss of carrier), the modem sends the release signal to the distant end, as in &T6, and reports the three- digit error count to the DTE. The information text is followed by an OK result code. See the V command for formats. The test is terminated by loss of carrier, or an H0, &T0, or Zn command, and by the timer timing out (S18 time out). Result Codes OK - when command execution is started. OK - after error count is sent to DTE. ERROR - if any other self test is active (&T1, &T3, &T6-&T8) ERROR - if not in Online Command State. ERROR - if command is issued at other than 1200 or 2400 bit/second. ERROR - if the RDL acknowledgment signal is not received. Execution Time Command execution lasts for the time it takes to receive the RDL acknowledgment signal, the test time, and time to send error count to DTE. DTE Interface Lines Affected DSR LEDs Affected MR flashes Cross Reference Commands - &Sn, &T0, &T6, H0, Zn S-registers - S18 DTE signals - DSR +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ &T8 - Local Loopback With Self Test ----------------------------------------------------------------------------------------------------------------------------- Command Line Format AT [cmds] &T8 [suffix] Suffix Values O or A Factory Default N/A Stored by &Wn N/A Displayed by &V N/A Description The modem goes on hook and is configured for analog loopback (low frequency band if none or O suffix, high frequency band if A suffix). The test timer is started at the time indicated by S18, DSR is turned off (if &S1 is in effect), AL Self-test state is entered, and an . OK result code is sent to the DTE during the test the modem sends a test message and counts errors in the looped back signal. The test is terminated when the timer times out (S18) or the &T0, H0, or Zn command is issued. When the test is terminated, the three-digit error count is sent to the DTE. An OK result code follows the error count. Result Codes OK - if AL Self-test state is entered. OK - after error count is sent to DTE. ERROR - if any other test is active (&T1, &T3, &T6, &T7), or if in the Online Command State. Execution Time Duration of the test and time to send error count to DTE. DTE Interface Lines Affected DSR LEDs Affected MR flashes Cross Reference Commands - &Sn, &T0, &T1, H0, Zn S-registers - S18 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ &T19 - Perform RTS/CTS Cable Test ------------------------------------------------------------------------- Command Line Format AT [cmds] &T19 Suffix Values N/A Factory Default N/A Stored by &Wn N/A Displayed by &V N/A Description This command is used with suitable DTE software to determine if the DTE cable used with a modem supports the RS-232C signals RTS and CTS. This procedure should be used by software before RTS/CTS flow control (&K3) is used. The modem takes the following action when this command is issued: 1. Turn OFF CTS (normally ON) and start a 500-ms timer. 2. Monitor RTS for ON and OFF states. 3. After the 500 ms timeout or when both level-high and level-low states of RTS are detected, restore CTS to the ON state and end the test. 4. If both states of RTS were NOT detected then return the ERROR result code; otherwise issue OK result code. The following steps describe what the DTE does to perform an &T19 test. Step 1: Send AT &T19 . Step 2: Wait for CTS to go off. If it goes off within 500 ms, then go to Step 3. Otherwise the test has failed. Step 3a: Turn off RTS, wait 50 ms, turn on RTS. Step 3b: Repeat Step 3a, up to 6 times. Step 4: If CTS goes on before the 6 iterations are completed, then go to Step 5. Otherwise, the test has failed. Step 5: Wait for a result code from the modem. If the result code is OK, then the test has passed. If ERROR, the test has failed (the DTE-DCE cable is not suitable for RTS/CTS flow control). +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ &Un - Disable Trellis Coding ------------------------------------------------------------------------- Command Line Format AT [cmds] &U [suffix] [cmds] Suffix Values 0 through 1 Factory Default &U0 Stored by &Wn yes Displayed by &V yes Description This command affects V.32 9600 bits/second only. * &U and &U0 - Enable Trellis coding (Factory Default) * &U1 - Disable Trellis coding +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ &V - View Configuration Profiles ----------------------------------------------------------------------------------------------------------------------------- Command Line Format AT [cmds] &V [0] [cmds] Suffix Values none Factory Default N/A Stored by &Wn N/A Displayed by &V N/A Description The active and stored profiles are displayed (commands and S-register settings) along with the stored telephone numbers. Inputs from the DTE are ignored while the view information is being sent to the DTE. The three-digit numbers after each S-register number are decimal representations of the S-register contents. An example of the information text is displayed below. This example resembles the &V info-text when the Factory Default profile is loaded and then stored into the stored profiles, and an arbitrary number is stored in one of the stored numbers. The and characters are not symbolically represented in this example in which V1 and Q1 are in effect. As usual, all and characters are defined by S-registers S3 and S4, respectively. Cross Reference Commands - &Wn, &Zn=x, &Yn, &F. &V Display Format The &V format for modems providing Dynamic Phone Storage is based on the following format: ACTIVE PROFILE: B1 B16 B30 B41 B60 B70 B75 B80 E0 L1 M1 N1 Q0 T V1 W0 X4 Y0 &A0 &C1 &D2 &G0 &J0 &K3 &L0 &Q5 &R0 &S0 &T4 &U0 &X0 &Y0 S00:000 S02:043 S03:013 S04:010 S05:008 S06:002 S07:090 S08:002 S09:006 S10:014 S11:060 S12:050 S25:005 S26:001 S36:007 S37:000 S38:020 S46:002 S48:007 S49:008 S50:016 S108:002 S109:062 S110:002 STORED PROFILE 0: B1 B16 B30 B41 B60 B70 B75 B80 E0 L1 M0 N1 P Q0 V1 W0 X4 Y0 &A0 &C1 &D2 &G0 &J0 &K3 &L0 &Q5 &R0 &S0 &T4 &U0 &X0 S00:000 S02:043 S06:002 S07:090 S08:002 S09:006 S10:014 S11:060 S12:050 S25:005 S26:001 S36:001 S37:009 S38:020 S46:002 S48:007 S49:008 S50:016 S108:002 S109:062 S110:002 STORED PROFILE 1: B1 B16 B30 B41 B60 B70 B75 B80 E0 L1 M0 N1 P Q0 V1 W0 X4 Y0 &A0 &C1 &D2 &G0 &J0 &K3 &L0 &Q5 &R0 &S0 &T4 &U0 &X0 S00:000 S02:043 S06:002 S07:090 S08:002 S09:006 S10:014 S11:060 S12:050 S25:005 S26:001 S36:001 S37:009 S38:020 S46:002 S48:007 S49:008 S50:016 S108:002 S109:062 S110:002 TELEPHONE NUMBERS: &Z0=9,7296558 &Z1= &Z2= &Z3= OK where: a. The selection of commands and registers are determined on a product by product basis. b. Four groups of information to be displayed are: * Active Profile * Stored Profile 0 * Stored Profile 1 * Stored Phone Numbers. c. In the first three groups, selected commands are displayed in alphanumeric order with one space between each starting at the next available display position from the following list: 17, or 21. Then selected S-registers are displayed in numeric order each starting at the next available display position from the following list: 1, 9, 17, 25, 33, 41, 49, 57, 65, or 73. d. The S-register entries are in the format Saa:vvv where; aa = the address of the register in decimal. vvv = the contents of the register in decimal. e. With the intent of packing as many commands and registers into the display as practical, the group headers, commands, and registers follow each other on the same lines where possible. Further, it is permissible to use the currently blank line between groups to expand the group displays. If this were done, there are no blank lines within the info-text area of the &V display. f. The phone number group has been modified to permit variable length phone numbers, provide an easy to read display, and minimize the number of display lines used. The traditional header line is removed, and in its place, each phone number begins with a mini-header consisting of the &Zn= command that would be used to program that memory. Each phone number begins on a new line for readability. If a phone number has more than 75 characters, a followed by 4 spaces is sent before the 76th character of the rest of that string. g. Only character positions 1-79 are used horizontally. It is desirable to keep the total number of lines used in the &V display and the associated verbose result code to 23 lines or less. This prevents the top line from scrolling off the top of terminal screens which have a 23 line limit. h. There is always one blank line between the body of the &V display and the verbose OK result code. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ &Wn - Store Active Profile ------------------------------------------------------------------------- Command Line Format AT [cmds] &W [suffix] [cmds] Suffix Values 0 through 1 Factory Default N/A Stored by &Wn N/A Displayed by &V N/A Description Certain commands and S-register contents are copied into one of the nonvolatile Stored Profiles by this command. * &W0 - Store the Active Profile into Stored Profile #0. * &W1 - Store the Active Profile into Stored Profile #1. The following items are stored: * current AT Speed and parity * current contents of certain S-registers. * current states of certain commands. See the S-register and command definitions to determine which are stored by the &W command. Execution Time 2 sec maximum plus time to transmit to DTE. Cross Reference Commands - Zn, &V, &Yn Processes - Hard Reset +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ &Xn - Select Sync Transmit Clock Source ----------------------------------------------------------------------------------------------------------------------------- Command Line Format AT [cmds] &X [suffix] [cmds] Suffix Values 0 through 2 Factory Default &X0 Stored by &Wn yes Displayed by &V yes Description This command determines how the DTE transmit clock is generated while the modem is in the synchronous mode. Note: This feature is available in OPTIMA products. * &X0 - The modem generates the transmit clock and applies it to pin 15 (RS-232). * &X1 - The DTE generates the transmit clock on pin 24 (RS-232) and the modem applies this clock to pin 15 (RS-232). * &X2 - The modem derives the transmit clock from the receive carrier signal and applies it to pin 15 (RS-232). DTE Interface Lines Affected Clock leads (Pins 15, 17, & 24) Cross Reference Commands - &Mn, &Qn DTE signals - SCTE, SCT, SCR +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ &Yn - Select Stored Profile For Hard Reset ----------------------------------------------------------------------------------------------------------------------------- Command Line Format AT [cmds] &Y [suffix] [cmds] Suffix Values 0 through 1 Factory Default none Stored by &Wn no Displayed by &V yes Description This command selects which stored profile is copied into the active profile subsequent to a hard reset (including power-up). The &Yn command execution is nonvolatile, it is stored in nonvolatile memory at the time that the &Yn command is executed, and it is not stored by the &Wn command. It is not affected by the &F command, but new modems have had &Y0 selected by the factory when shipped. * &Y0 - Select Stored Profile #0 on Hard Reset. * &Y1 - Select Stored Profile #1 on Hard Reset. Cross Reference Commands - Zn Processes - Hard Reset +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ &Zn= - Store Telephone Number Description Used to store up to four dialing strings. These stored dial strings are non-volatile (survive power outages). Refer to the D command and to the Dial Modifiers to determine valid dial strings. If no dial string is used, then the referenced stored number is cleared. &Z syntax AT [cmds] &Z[[n]=] [dial_string] where: a. All characters that follow the &Zn= command until the carriage return are treated as dial_string entry. b. If the = token is present in the next position after the &Z, then string 0 is assumed. c. If the = token is present in the second position after the &Z, address then the first position after the &Z must be a valid phone string (n). Valid values for n are 0, 1, 2, or 3. If the character is not a valid (n), then an ERROR results. d. If no = token is found in either the first or second position after the &Z , then location zero is assumed, and the remainder of the command line is the candidate dial string for location 0. e. If the dial_string is missing, the memory is cleared. f. The following characters are storable in dial_strings; 0123456789ABCD#*,"$TPRW@!; g. Other characters are ignored, not stored. Further, disposition of characters following a ; (semicolon) dial are not modifier in an &Z entry are not specified. If such characters stored, they are ignored. h. Lower case letters entered are converted into upper case for storage. i. Available Space is defined as the storage area being used by the pre-existing string in the target location, plus any phone number space not currently in use by the other three phone strings. It is assumed that the present phone number space consisting of 4x36=144 characters continues to be the total size of the non-volatile memory phone number area. j. If the string of "storable" characters does not fit into the available space, then no change to the pre-existing stored string occurs. The command produces ERROR. Example: assume String 0 uses 20 characters; String 1 uses 30 characters; String 2 uses 50 characters; and String 3 uses no characters. There are 44 characters free. Attempts to store 64 storable characters in String 0 would produce an OK result code, but 65 characters would produce an ERROR result code. Suffix Values 0 through 3 Factory Default N/A Stored by &Wn N/A Displayed by &V yes Execution Time 500 ms maximum Cross Reference Commands: S=n, &V +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ , Perform Pause ------------------------------------------------------------------------- Command Line Format AT [cmds] , [cmds] Suffix Values none Factory Default N/A Stored by &Wn N/A Displayed by &V N/A Description Pause for the amount of time specified by S8 (in seconds) before processing the next character in the command string. This command is also a dial modifier. Execution Time S8 seconds Cross Reference Commands - Dn, comma dial modifier S-registers - S8 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ = - Write To An S-Register This is an abbreviated form of the Sn=x command. Refer to the Sn= command for a complete description. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ? - Read An S-Register This is an abbreviated form of the Sn? command. Refer to the Sn? command for a complete description. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ P - Select Pulse Dialing ----------------------------------------------------------------------------------------------------------------------------- Dial String Format [digits and modifiers] P [digits and modifiers] Factory Default P (as opposed to D) Stored by &Wn yes Note: P may also be used as a command. Whether P is executed as a command or as a dial modifier, the effect is the same. The current choice of dialing method (P or T) may be stored in Profiles. As a Dial Modifier, P may also be a part of a dial string that is stored in one of the four stored numbers. Refer to the &Zn= command. Displayed by &V yes Description This dial modifier instructs the modem to use pulse dialing. Dialed digits are pulse-dialed in subsequent digits of the current dial string and in all future dial strings until a T command or dial modifier is executed. Execution Time 1 ms maximum Cross Reference Commands - Dn, T, P +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ T - Tone ------------------------------------------------------------------------- Dial String Format [digits and modifiers] T [digits and modifiers] Stored by &Wn yes Note: T may also be used as a command. Whether T is executed as a command or as a dial modifier, the effect is the same. The current choice of dialing method (P or T) may be stored in Profiles. As a Dial Modifier, T may also be a part of a dial string that is stored in one of the four stored numbers. Refer to the &Zn command. Displayed by &V yes Stored by &Wn yes Description The T dial modifier instructs the modem to send DTMF tones while dialing. Dialed digits are tone dialed until a P command or P dial modifier is selected. Execution Time 1 ms maximum Cross Reference Commands - Dn, P, T command ========================================================================= Chapter 5 Result Codes ************************************************************************* Basic Result Codes Short Form Result Code MEANING ------------------------------------------------------------------------- ----- 0 OK Acknowledges entry into either the idle state or the Online Command State after successful execution of a command line, Hayes Patented, or "DTR-escape". There may be instances for which the modem does not actually execute a command but returns OK anyway. This is done to provide compatibility with some communication software. 1 CONNECT A connection has been established at unstated line and DTE speeds if the X0 command is in effect; a connection has been established at a line and DTE speed of 0 to 300 bit/second if X0 is not in effect. 2 RING Ringing voltage on and off has been detected. 3 NO CARRIER Failure to connect or loss of carrier. 4 ERROR Command not recognized. Command line too long. Response to I command, incorrect check sum. Command issued at 110 or 300 bit/second and a synchronous mode in effect. 5 CONNECT 1200 A connection has been established and the DTE should change its port speed to 1200 bit/second. 6 NO DIALTONE Dial tone detection was attempted but not found within the time out period. Blacklisting may also cause the modem to detect no dial tone. 7 BUSY A busy signal has been detected. 8 NO ANSWER The @ Wait For Quiet Answer dial modifier was executed, and 5 seconds of silence was not detected. 10 CONNECT 2400 A connection has been established and the DTE should change its port speed to 2400 bit/second. ************************************************************************************************** Extended Result Codes Extended Result Codes Numeric Verbose Numeric Verbose -------------------------------------------------------------------------------------------------- 11 CONNECT 4800 56 CARRIER 38400 12 CONNECT 9600 57 CARRIER 56000 13 CONNECT 14400 58 CARRIER 57600 14 CONNECT 19200 59 CARRIER 64000 15 CONNECT 28800 60 CONNECT 21600 16 TIMEOUT 61 CONNECT 20800 17 CONNECT 56000 62 CONNECT 41600 18 CONNECT 57600 63 CONNECT 51200 19 CONNECT 64000 64 CONNECT 62400 20 CONNECT 0600/75 65 CONNECT 230400 21 CONNECT 75/0600 66 COMPRESSION: CLASS 22 CONNECT 1200/75 67 COMPRESSION: V.42BIS 23 CONNECT 75/1200 68 Not applicable 24 CONNECT 7200 69 COMPRESSION: NONE 25 CONNECT 12000 70 PROTOCOL: NONE 26 CONNECT 16800 71 Not applicable 27 CALL WAITING 72 Not applicable 28 CONNECT 38400 73 Not applicable 29 CONNECT 24000 74 Not applicable 30 CONNECT 33600 75 Not applicable 31 CONNECT 115200 76 Not applicable 32 CONNECT 48000 77 PROTOCOL: LAP-M 33 FAX 78 Not applicable 34 CONNECT 26400 79 Not applicable 35 DATA 80 PROTOCOL: ALT 36 CARRIER 26400 81 Not applicable 37 CARRIER 24000 82 Not applicable 38 CARRIER 21600 83 Not applicable 39 CARRIER 48000 84 Not applicable 40 CARRIER 300 85 Not applicable 41 CARRIER 600 86 PROTOCOL: FAX 42 CARRIER 600/75 87 Not applicable 43 CARRIER 75/600 88 Not applicable 44 CARRIER 1200/75 89 Not applicable 45 CARRIER 75/1200 90 Not applicable 46 CARRIER 1200 91 Not applicable 47 CARRIER 2400 92 Not applicable 48 CARRIER 4800 93 Not applicable 49 CARRIER 7200 94 Not applicable 50 CARRIER 9600 95 Not applicable 51 CARRIER 12000 96 Not applicable 52 CARRIER 14400 97 Not applicable 53 CARRIER 16800 98 Not applicable 54 CARRIER 19200 99 Not applicable 55 CARRIER 28800 ========================================================================= Chapter 6 S-registers ************************************************************************* Introduction +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Scope S-register commands are provided to allow the DTE to read or write certain modem parameters. This Chapter defines S-register functions, and syntax and evaluation rules. The modem does not support any S-registers that are not identified in the Chapter. The names of unidentified registers should be considered reserved. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Command Lines The valid forms for S-register commands are: Command Line Form Note ------------------------------------------------------------------------------------------------------- AT Sn= value is stored in Sn AT Sn= value 0 is assumed AT S= S0 is assumed AT S= S0 and value 0 are assumed AT = last Sn is assumed AT = last Sn and value 0 are assumed AT Sn? the value of Sn is sent to DTE AT ? last Sn is assumed AT S? S0 is assumed Note: The symbols S, ?, and = are all separate commands. The number n is called the address. Other commands may precede or follow S-register commands, subject to the restrictions of the other commands. In command lines, the numbers n and are expressed as ASCII-coded decimal digits. The number of digits used to express n and is limited only by the length of the resulting command line. Leading zeros in an S-register address or value are echoed but ignored. Thus S00012 is the same as S12 and S10=000025 is the same as S10=25. Modems accept values up to 255 and may accept larger values. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Default Value The phrase default value, in this Chapter, means the value that is established by the &F command. The value left in a register after factory testing may not be the default value. ************************************************************************************************** Types A value-mapped register is one whose value is interpreted as the value of a modem parameter. Such registers have ranges of valid values. A bit-mapped register is one whose value is interpreted as a set of bits whose binary values separately control modem parameters. Bit 0 is the least significant bit. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Behavior Of Unimplemented S-registers The Sn? command to an unimplemented register is not regarded as erroneous, and the modem does not exit the command line because of it. The info-text for this command is always 000 with normal and characters. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Classifications Of S-registers S-registers are classified in several ways. a. Valid registers have addresses that are between zero and some upper limit (the upper limit for most modems is 255). Negative addresses are invalid. The modem remembers the last used address. After power-up or reset, the last used address is 0. Attempts to point to an invalid address do not change the last used address. b. A register to which RAM space has been assigned is said to exist. Only registers whose addresses are valid exist. c. Implemented registers are registers that exist and perform a defined modem function, and these definitions are presented. d. Unimplemented registers are those that exist but serve no function. A modem may contain some unimplemented registers. Some are mandatory for backward compatibility. Others are included as a convenience in the firmware design. e. Value-Mapped registers are those whose values represent modem parameters. f. Bit-Mapped registers are those whose individual bit values represent modem parameters but the total value does not. g. Read-Only registers are those whose values may be read but not altered by the = command. These registers are normally used to present the current status or outcome of an event or process. h. Non-volatile registers are those whose values remain after a loss of power. Non-volatile registers are not stored by the &Wn command. i. Stored Registers are those which may be copied into a stored profile by the &Wn command. ************************************************************************************************** Value Evaluation Rules Value evaluation rules define the outcome of the write operations performed by the = command to registers that exist. Value mapped Value-mapped register values have bounds. Write commands with values that are within the bounds are accepted. If an attempt is made to write a value that is outside of the allowed range, then the outcome is (1) below unless (2) is specified in the register description. 1. The bound value that is closest to the entered value is written and an OK result code returned. 2. The register value is not changed and the ERROR result code is returned. Bit mapped The bits to be written to a bit-mapped register are determined from the binary number equivalent to the decimal value entered in a write command. Bits indicated by the value that are defined is written. Unused bits indicated by the value are ignored and their values set to 0. For example, if the value 10 is given in a write command (binary 1010) to a register for which only bits 0, 1, and 2 are used, then bits 0, 1, and 2 are set to 0, 1, and 0, respectively, and all other bits set to 0. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Summary Of S-register Behaviors The following figure illustrates the reading and writing rules. The illustration refers to numbers 1-6 in the S-register Commands, refer to the chart following the illustration for definitions of the S-register commands for the six possible S-register values. S-register Rules S-register Commands S[n][? [ =[ Pointer/Result Code Read/Result Code Write/Result Code ------------------------------------------------------------------------------- Valid Address (no) Don't Point,ERROR N/A N/A Exist (no) Point, OK Say 000, OK Don't Write, OK Implemented (no) Point, OK Say 000, OK Don't Write, OK Read Only (no) Point, OK Read xxx, OK Don't Write, OK Bit Mapped type Point, OK Read xxx, OK Write bits, OK Value Mapped type Point, OK Read xxx, OK Write clamps, OK +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S0 - Ring After Which To Answer Description Establishes the number of the rings after which the modem answers (first, second, third, etc.). A value of from 1 to 255 places the modem in auto-answer mode. Setting S0 to 0 disables auto-answer mode. The AA LED on the front panel is illuminated when S0 contains a number larger than zero. Type value Value range 0 to 255, Default value: 0 Stored by &Wn yes Displayed by &V yes +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S1 - Ring Count ----------------------------------------------------------------------------------------------------------------------------- Description S1 is incremented each time the modem detects a ring signal on the telephone line, while the command process is not active, and is cleared if no rings occur over any eight-second interval. Type value Value range 0 to 255, Default value: 0 Stored by &Wn no Displayed by &V no +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S2 - Hayes Escape Character ----------------------------------------------------------------------------------------------------------------------------- Description S2 contains the decimal value of the ASCII character used for the escape character. The default value corresponds to an ASCII "+". See the "Hayes Improved Escape Sequence with guard time " in Chapter 8. A disables the Hayes Patented Escape Process with guard time. That is, no escape value over 127 character is recognized. Values for S2 are stored in nonvolatile memory profiles by the &Wn commands. Type value Value range 0 to 255, Default value: 43 Stored by &Wn yes Displayed by &V yes +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S3 - Carriage Return Character ----------------------------------------------------------------------------------------------------------------------------- Description S3 holds the decimal value of the ASCII character used to represent . The default value represents an ASCII CR. Type value Value range 0 to 127, Default value: 13 Stored by &Wn no Displayed by &V yes +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S4 - Line Feed Character ----------------------------------------------------------------------------------------------------------------------------- Description S4 holds the decimal value of the ASCII character used to represent . The default value represents an ASCII LF. Type value Value range 0 to 127, Default value: 10 Stored by &Wn no Displayed by &V yes +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S5 - Backspace Character ----------------------------------------------------------------------------------------------------------------------------- Description S5 holds the decimal value of the ASCII character used for . The default value represents an ASCII BS. Type value Value range 0 to 32, 127 Default value: 8 Stored by &Wn no Displayed by &V yes +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S6 - Wait Before Blind Dialing ----------------------------------------------------------------------------------------------------------------------------- Description The value in S6 determines how long the modem waits after going off hook before blind dialing. See the D and Xn commands in Chapter 4. Type value (seconds) Value range 2 to 255, Default value: 2 Stored by &Wn yes Displayed by &V yes +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S7 - Wait For Carrier ----------------------------------------------------------------------------------------------------------------------------- Description The value in S7 sets the time limit for the following events. * wait for silent answer (@ dial modifier) * wait for dial tone (W dial modifier) * wait for carrier completion of handshaking timeout. See also D command, @ dial modifier, W dial modifier, in Chapter 4 plus "Dialing Process", and "Handshaking Process" in Chapter 8. Type value (seconds) Value range 1 to 255, Default value: 50 Stored by &Wn yes Displayed by &V yes +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S8 - Pause Time For Comma ----------------------------------------------------------------------------------------------------------------------------- Description Establishes the duration of the pause when a comma (,) is encountered in a command line or dial string. Type value (seconds) Value range 0 to 255, Default value: 2 Stored by &Wn yes Displayed by &V yes +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S9 - Carrier Recovery Time ----------------------------------------------------------------------------------------------------------------------------- Description The number of tenths of a second in S9 is the time delay between a return of carrier, in the online state, and the acceptance of the carrier. Carrier is considered to have been detected S9 time after the bit pump reports carrier present. See also S10. See "Carrier Detection" in Chapter 8. Note: Answer tone and carrier detection timing during the handshake process is not timed by S9. Type value (deciseconds) Value range 1 to 255, Default value: 6 Stored by &Wn yes Displayed by &V yes +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S10 - Lost Carrier Hang Up Delay ----------------------------------------------------------------------------------------------------------------------------- Description The time specified in S10 is the length of time in tenths of seconds that a carrier may remain undetected, in the online state, before the modem starts the hang-up process. If carrier is lost and its return is not reported by the bit pump for a time equal to the difference in times indicated by the values of S9 and S10, then the modem should start the hang-up process. If carrier does return before the time limit, the carrier must persist for the S9 time before the modem will consider carrier to be on. If S10 is set to 255, the modem does not hang up when carrier is lost (and the modem continues to send its modulated carrier). The modem may attempt a retrain, but may not hang-up. See "Carrier Detection" in the Chapter 8. Type value Value range 1 to 255, Default value: 14 Stored by &Wn yes Displayed by &V yes +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S11 - DTMF Dialing Speed ----------------------------------------------------------------------------------------------------------------------------- Description The time specified by S11 is the duration of a DTMF tone pulse and the time between consecutive pulses. Type value (milliseconds) Value range 50 to 255, Default value: 95 Stored by &Wn yes Displayed by &V yes +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S12 Hayes Escape Guard Time ----------------------------------------------------------------------------------------------------------------------------- Description The time specified by S12 is the guard time used by the Hayes Patented Escape Process with guard time. See Chapter 8. Type value (1/50 second) Value range 0 to 255, Default value: 50 Stored by &Wn yes Displayed by &V yes +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S16 - Test in Progress ----------------------------------------------------------------------------------------------------------------------------- Description The bits of this S-register indicate which tests are in progress. Type bit mapped, read only Value range 0 to 127, Default value: 0 Stored by &Wn no Displayed by &V no Bit Map Bit Meaning --------------------------------------------------------------------------- 0 Local analog loopback is enabled 1 Reserved 2 Local digital loopback is enabled 3 Remote digital loopback (at this end) enabled 4 Remote digital loopback enabled 5 Remote digital loopback with self test enabled 6 Local analog loopback with self test enabled 7 Reserved +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S18 - Modem Test Timer ----------------------------------------------------------------------------------------------------------------------------- Description Establishes duration of modem's diagnostic tests. When a test is active for a length of time equal to the value chosen for this register, the modem automatically cancels the test. A setting of zero (0) disables the test time and allows a test to run indefinitely. Type value Value range 0 to 255, Default value: 0 Stored by &Wn yes Displayed by &V no +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S19 - AutoSync Options ----------------------------------------------------------------------------------------------------------------------------- Description Defines options for Hayes AutoSync operation. Note: NRZI coding is only valid in HDLC mode. Note: This S-register is available in OPTIMA products. Type bit mapped, Default value: 0 Stored by &Wn no Displayed by &V no Bit Map Bit Meaning ------------------------------------------------------------------------- 0 reserved 1 0 selects BSC (default) 1 selects HDLC 2 0 disables HDLC address detection (default) 1 enables HDLC address detection 3 0 selects NRZI bit encoding (default) 1 selects NRZ bit encoding 4 0 selects mark idle (default) 1 selects flag or sync idle 5 0 selects AutoSync (default) 1 selects AutoSync II 6 reserved 7 reserved +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S25 - Detect DTR Change ------------------------------------------------------------------------- Description If &Q1 is in effect, then S25 is the delay in seconds after a connection has been made (and the modem has gone to the online state), but before the modem examines the DTR lead. This delay allows you sufficient time to disconnect the modem from an asynchronous terminal to attach the modem to a synchronous terminal, without forcing the modem back to the command mode. If &Q4 is in effect and bit 5 of S19 is 0 (AutoSync selected), then S25 sets the time in seconds that the modem pauses after a connection is established. This gives the DTE time to reset its serial port to 9600 bits/second, 8 data bits, mark parity, and one stop bit. This feature is not used with AutoSync II operation. For any &Qn command in effect, if in the dialing, handshaking, online, or Online Command State, DTR excursions from ON to OFF that last less than the time specified by S25, in 0.01 sec increments, are ignored by the modem. (If &D3 is in effect, it overrides the effect of S25 and results in instantaneous effect of DTR ON to OFF). The value of S25 has no effect on recognition of ON-to-OFF transitions of DTR while the modem is in the idle state. Type value (seconds or centiseconds) Value range 0 to 255, Default value: 5 Stored by &Wn yes Displayed by &V yes +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S26 - RTS To CTS Delay Interval ----------------------------------------------------------------------------------------------------------------------------- Description If &R0 is selected, the modem waits the length of time specified by S26 in 10 ms increments before turning on CTS in response to an off-to-on change in RTS. See &R command in Chapter 4. Note: This S-register is available in OPTIMA products. Type value (centiseconds) Value range 0 to 255, Default value: 1 Stored by &Wn yes Displayed by &V yes +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S30 - Inactivity Timeout ----------------------------------------------------------------------------------------------------------------------------- Description The modem enters the hang-up process whenever both the DTE and the DCE are inactive for a time greater than the value contained in this register, in tens of seconds. This function is disabled when the register contains the value 0, which is the default. This register is ignored in leased-line operation. Type value (decaseconds) Value range 0 to 255, Default value: 0 Stored by &Wn yes Displayed by &V no +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S31 - XON Character ----------------------------------------------------------------------------------------------------------------------------- Description This register defines which ASCII character is used as the XON character in software (start/stop) flow control. This register does not affect the character in used in transparent flow control. Type value Value range 0-255, Default value: 17 (DC1) Stored by &Wn yes Displayed by &V no +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S32 - XOFF Character ----------------------------------------------------------------------------------------------------------------------------- Description This register defines which ASCII character is used as the XOFF character in software (start/stop) flow control. This register does not affect the character used in transparent flow control. Type value Value range 0-255, Default value: 19 (DC3) Stored by &Wn yes Displayed by &V no +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S36 - Negotiation Failure Treatment ----------------------------------------------------------------------------------------------------------------------------- Description When an error-control connection cannot be negotiated between the two modems, this register indicates which operating mode the modem will use. Note that if negotiation is disabled (S48=128), these fallback options are initiated immediately. In products supporting MNP 5, which negotiated class is determined by the setting in S46. Bit 2 of that register is the master compression bit which if on (values 2, 3, 138) will result in MNP Class 5 negotiation and if off (values 0, 1, 136) results in MNP Class 4 negotiation. Type bit mapped Value range 0-7, Default value: 7 Stored by &Wn yes Displayed by &V yes Bit map Bit Meaning ---------------------------------------------------------------- 0 0=hangup, 1=fall back according to bit 1 1 0=direct async, 1=first try ASB 2 0=do not try MNP, 1=first try MNP then according to bits 0 and 1. 3 reserved 4 reserved 5 reserved 6 reserved 7 reserved Value meanings S36 First Choice Second Choice ------------------------------------------------------------------ 0 Hang-up N/A 1 Async Hang-up 2 Hang-up N/A 3 Buffered Async Hang-up 4 MNP Hang-up 5 MNP Async 6 MNP Hang-up 7 MNP Buffered Async Cross Reference S48 Feature Negotiation Action S46 Protocol Selection +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S37 - Desired DCE Line Speed ----------------------------------------------------------------------------------------------------------------------------- Description During carrier handshake the modem attempts to connect at the highest supported data rate that does not exceed the value entered in this register. This applies to originated and answered calls; S37 sets the upper speed limit. Lower speeds may be negotiated if the appropriate Nn command is selected. When doing a V.32, V.32 bis, or V.FC handshake, the modem connects only at speeds enabled by S109. If Ans-A or Orig-A handshake behavior is selected (defined for Nn command) and the speed indicated by S37 is one of the set covered by S109, then the speed must match one of the speeds selected by S109 or when the modem enters the handshake process the modem sets S86 to value 16, hangs-up, and sends NO CARRIER result code. If the speed and modulation combination selected by S37 and the corresponding Bn command is not one of those affected by S109, then the handshake proceeds normally. See the description of S109 for the affected modulations. If the DTE enters a reserved or undefined value for S37, the modem returns ERROR and does not change the value. Type value Value range see list below, Default value: 0 Stored by &Wn yes Displayed by &V yes Parameter Value Meanings ------------------------------------------------ 0 Use Last AT Speed 1 Reserved (75) 2 Reserved (110) 3 300 4 Reserved (600) 5 1200 6 2400 7 4800 8 7200 9 9600 10 12000 11 14400 26 16800 12 19200 33 21600 29 24000 34 26400 15 28800 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S38 - Hang-up Timeout ------------------------------------------------------------------------- Description The following applies to calls during which data may be buffered. If the modem detects loss of carrier or a clear-call message from the distant modem, or the DTE requests that the call be cleared (by ATH or DTR going off while &D2 is selected), then the modem starts a timer at time specified by S38 and does the following. 1. If hanging up at user's request (ATH command or DTR goes off), then the modem discards the receive buffer and transmits contents of transmit buffer. After this is done, the modem conducts orderly shutdown of error-control protocol (if any). If the contents of the transmit buffer are sent before the S38 time limit, then the modem hangs up and returns the OK result code. If the timer expires before the contents are sent, then the modem hangs up and returns the NO CARRIER result code. An S38 value of 0 forces the NO CARRIER result. 2. If hanging up because of loss of carrier, orderly shutdown initiated by other side, or protocol failure, then the modem discards the transmit buffer, goes on hook, and sends the contents of receive buffer to the DTE for the time set by the value of S38. When the time limit is reached or the buffer contents are sent to the DTE, the modem returns the NO CARRIER result code. If the modem is blocked from sending buffered data to the DTE because of flow control, then the modem continues to attempt to send the data and terminates the attempt or the sending when the timer expires. This register does not affect AutoSync II operation; buffered data is discarded. Type value (seconds) Value range 0 to 255, Default value: 20 Stored by &Wn yes Displayed by &V yes Parameter Values 0-254: Number of seconds to send buffered data before clearing the call. 255: Modem sends all buffered data and then clears the call (no time limit). Note: If the connection is lost, the modem does not attempt to send any more buffered data. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S43 - Current Line Speed ----------------------------------------------------------------------------------------------------------------------------- Description The value in this register indicates the line speed of the last carrier established. Type value, read only Value range 0, 2-12, 15, 26, 29, 33, 34; Default value: 0 Stored by &Wn no Displayed by &V no Values meanings Parameter Value Meanings -------------------------------------------- 0 No Connection 1 Reserved (75) 2 110 3 300 4 600 5 1200 6 2400 7 4800 8 7200 9 9600 10 12000 11 14400 26 16800 12 19200 33 21600 29 24000 34 26400 15 28800 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S44 - Framing Technique ------------------------------------------------------------------------- Description Permits you to specify error-control connection type. Type value Value range 2, 3: Default value: 3 Stored by &Wn yes Displayed by &V no Parameter Values 2: Negotiate asynchronous only, if MNP attempt. This can be used to force an MNP-2 connection for tests. 3: Negotiate either synchronous (preferred) or asynchronous if MNP. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S46 - Protocol/Compression Selection ----------------------------------------------------------------------------------------------------------------------------- Description When &Q5 is selected, S46 permits you to select whether or not to negotiate compression, and to select the priority for negotiating protocols, if any. When negotiating MNP, the class negotiated is determined by bit 1. MNP Class 5 is negotiated if bit 1 is set, and MNP Class 4 is negotiated if it is cleared. Type bit mapped Value range 0 to 31, Default value: 2 Stored by &Wn yes Displayed by &V yes Bit Map Bit Value Meanings -------------------------------------------- 0 Ignored 1 Enable compression 2 Ignored 3 Ignored 4 Prevent LAPM protocol 5 Ignored 6 Ignored 7 Ignored Cross Reference S48 Feature Negotiation Action, S36 Negotiation Fallback, Chapter 8. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S48 - Feature Negotiation Action ------------------------------------------------------------------------- Description V.42 Feature Negotiation has two phases: detection and negotiation using XID frames. This register permits you to disable the V.42 detection phase. Type bit mapped Value range 0 to 7, 128-135, Default value: 7 Stored by &Wn yes Displayed by &V yes Bit Map Bit Value Meanings ------------------------------------------------ 0 Not used 1 Not used (XID negotiation always enabled) 2 Enable XON/Escape Detection Phase 3 Not used 4 Not used 5 Not used 6 Not used 7 Force fallback Cross Reference S46 Protocol Selection, S36 Negotiation Fallback +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S49 - Buffer Low Limit ------------------------------------------------------------------------- Description This S-register, in conjunction with S50 (Buffer High Limit) determines the number of characters which are buffered in Automatic Speed Buffering (ASB) and error-control modes before the DTE is flow controlled. When the number of characters in the buffer reaches the value set by this register, the DTE is flowed on. If the value of S49 is larger than the value of S50, then the values are interchanged during the next handshake. If the value of S49 equals the value of S50, then the value of S49 is reduced by one during the next handshake. Note: This feature is available in 28.8 kbits/second modems. Type value Value range 1 to 249, Default value: 64 Stored by &Wn yes Displayed by &V yes Cross Reference &Q5 Error Control Mode, &Q6 Automatic Speed Buffering Mode, S36 Negotiation Fallback Options, S50 ASB: High Limit +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S50 - Buffer High Limit ------------------------------------------------------------------------- Description This S-register, in conjunction with S49 (Buffer Low Limit) determines the number of characters which are buffered in Automatic Speed Buffering (ASB)and error-control modes before the DTE is flow controlled. When the number of characters in the buffer reaches the value set by this register, the DTE is flowed off. If the value of S49 is larger than the value of S50, then the values are interchanged during the next handshake. If the value of S49 equals the value of S50, then the value of S49 is reduced by one during the next handshake. Note: This feature is available in 28.8 kbits/second modems. Type value Value range 2 to 250, Default value: 192 Stored by &Wn yes Displayed by &V yes Cross Reference &Q5 Error Control Mode, &Q6 Automatic Speed Buffering Mode, S36 Negotiation Fallback Options, S49 ASB: Low Limit +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S70 - Maximum Number of Retransmissions ----------------------------------------------------------------------------------------------------------------------------- Description S70 sets the number of times the modem retransmits a frame while using while using error-control link layer protocol. Retransmissions become necessary when data errors introduced by noise disrupt the reception of a frame. When the limit set by S70 is reached, the modem hangs up. Raising this limit may be necessary if, for example, telephone lines are extremely noisy. See also parameter N400 in CCITT Recommendation V.42. Note: This feature is available in 28.8kbits/second OPTIMA modems. Type value Value range 1-255, Default value: 10 Stored by &Wn yes Displayed by &V no +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S73 - No Activity Timeout ----------------------------------------------------------------------------------------------------------------------------- Description The modem sends an RR frame to the distant modem after inactivity (no data sent or received) for the time specified by S73. See also T402 in CCITT recommendation V.42. Note: This feature is available in 28.8 kbits/second OPTIMA modems. Type value (seconds) Value range 1-255, Default value: 5 Stored by &Wn yes Displayed by &V no +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S82 - Break Selection ----------------------------------------------------------------------------------------------------------------------------- Description This register determines how breaks are transmitted during error-control and ASB calls. The following options are provided. In-sequence means a break is sent to the distant end after any buffered data, without disrupting the data being transmitted. Incoming data is sent to the local DTE after any buffered data. Expedited means breaks are sent to the distant end or delivered to the DTE before any buffered data, while maintaining the integrity of the data. Destructive means all buffered data is discarded before the break is sent; the buffered data is lost. Destructive implies expedited; the break is sent instead of buffered data. Thus destructive and expedited breaks occur if the value of bit 2 is 1, independent of bit 1. V.42 LAPM provides a means for the sending end to tell the receiving end when a break is timed or not. The receiving modem delivers breaks that are timed according to the indication from the distant modem. When using LAPM, timed break duration's are in increments of 10 ms. Timed breaks are sent with duration equal to the closest time increment that is not less than the duration received from the DTE. If a V.42 Alternative Procedure connection is made then the modem only provides untimed breaks; bit 0 is ignored. The procedure does not include a means for timed breaks. When using ASB, timed breaks are timed according to the procedure described in V.14: breaks that last M to 2*M + 3 bits are sent with duration 2*M + 3 bits. Longer breaks are sent with their true duration. Less than M spacing bits from the DTE are ignored, not treated as breaks. The duration of untimed breaks is the larger of 180 ms or 2M + 3 bits (M is the length of a character). When using ASB, incoming breaks are delivered to the DTE in sequence, after any other buffered data. Note: V.14 specifies how breaks are handled when that recommendation is in use. Type bit mapped, Factory Default Value: 1 Stored by &Wn yes Displayed by &V no Bit Map Bit Value Meanings --------------------------------------------------- 7 0 = untimed, 1 = timed (for compatibility) 6 reserved 5 reserved 4 reserved 3 reserved 2 0 = not destructive, 1 = destructive 1 0 = in sequence, 1 = expedited 0 0 = untimed, 1 = timed +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S86 - Connection Failure Cause Code ----------------------------------------------------------------------------------------------------------------------------- Description This read-only register indicates why a connection failed or was otherwise concluded (either the desired protocol was not negotiated, carrier loss, normal hang-up, etc.). The modem places a value in this register whenever a NO CARRIER result code is returned. Although several events may contribute to the connection failure, S86 reports the first event which caused the failure. The value of S86 is set within 10 ms of the NO CARRIER result code (the end of the trailing Ctrl-J) and is unchanged until the next NO CARRIER result code is sent to the DTE. Type value, read only Value range listed below, Default value: 0 Stored by &Wn no Displayed by &V no Value Meanings Value Meaning ------------------------------------------------- 1 Normal hang-up from FAX call 2 Reserved 3 Reserved 4 Lost carrier 5 Feature negotiation failed to detect presence of another error- control modem at the remote end. 6 Other error-control modem did not respond to feature negotiation message sent by this modem. 7 Other modem is synchronous-only, this mode is asynchronous only. 8 Modems could not find a framing technique in common (async or sync). 9 Modems could not find a common protocol. 10 Feature negotiation message sent by remote modem is incorrect. 11 Synchronous information (data or flags) not received from other modem. Modem waits 30 seconds before hanging up. 12 Normal disconnect initiated by remote modem. 13 Remote modem did not respond after many transmissions of the same message. Modem attempts connection 10 times before giving up. 14 Protocol violation occurred. 15 Compression failure. 16 Speed indicated by S37 did not match any of the speeds indicated by S109. 17 Hang-up was due to S116 time out. 18 Inactivity timer S30 caused hang-up. 19 Long space disconnect hang-up. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S91 - Select Dial-up Line Transmit Level ----------------------------------------------------------------------------------------------------------------------------- Description This register selects the transmit carrier level of the modem in dBm [into 600 ohms]. This register is only functional in certain International (non-US) products. The nominal output level is between 0 and 1 dB less than the indicated level and the actual level of any unit does not exceed the indicated level by more than 1 dB. The value of this register is stored when written. This register is locked (write commands do not change current value) while the modem is in the online states and normally locked in the off-line command state. The register may be unlocked, changed, and locked for the off-line command state by the following steps. Note: This feature is not available in all OPTIMA and ACCURA products. Step 1: Turn off modem. (Remove cover first.) Step 2: Operate the switch (inside modem cover) intended to enable transmit level adjustment. This is usually SW2 of a DIP switch. Step 3: Turn on modem. Step 4: Write a new value to the register using the syntax AT S91=nn. Step 5: Turn off the modem. Step 6: Move the switch to the disable position. Step 7: Turn on the modem. The modem will now operate with the new transmit level. Type value (- dBm) Value range 0 through 15, Default value: 10 Stored by &Wn N/A Displayed by &V no Note: The output level is not adjustable in the US. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S95 - Extended Result Code Bit Map ------------------------------------------------------------------------- Description The bits in this register may be set to force some of the characteristics of the Wn command ON. If any of the bits below are set to 1, then the corresponding result code is enabled regardless of the Wn or Xn (n > 1) command in effect. Refer to the Wn and Xn commands for additional information. This register does not affect the result codes selected by the X0 command. Type bit mapped, Default value 0 Stored by &Wn yes Displayed by &V no Bit Function Value Bit Function ------------------------------------------------- 1 0 CONNECT result code (verbose or numeric) indicates the line speed (rather than the DTE speed). 2 1 Append "/ARQ" to the verbose CONNECT result code if the protocol is not "NONE". Example: "CONNECT 9600/ARQ". 4 2 Enable the CARRIER result codes. 8 3 Enable the PROTOCOL result codes. 16 4 reserved 32 5 Enable the COMPRESSION result codes. 64 6 reserved 128 7 reserved +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S97 - V.32 Late Connecting Handshake Timing ------------------------------------------------------------------------- Description During a V.32 automode handshake, the answer modem sends unscrambled binary ones (USB1) for the time called Ta. The value of S97 sets the duration of Ta. During the handshake, the originate modem waits a time, Tc, to check for USB1. Tc is Ta plus 0.1 s. S97 only affects Ta and, indirectly, Tc. If an answer mode modem is set to answer at 2400 bit/second, S97 has no impact on how long USB1 is transmitted. If the automode handshake sequence repeats itself, as when V.21 and V.23 are included, then S97 affects all cycles. The Factory Default favors the existing installed base of modems. S97 may have a value from 15 to 70. Each unit of S97 corresponds to 0.1 s in Ta. Set S97 to 15 (1.5 sec) when compatibility with V.32 late connecting modems is a primary requirement. Type value (15-70), Default value 30 Stored by &Wn yes Displayed by &V no +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S105 - Frame Size ------------------------------------------------------------------------- Description This value indicates the maximum link layer frame information field size that is attempted with the V.42 protocol. The value equals the log (to the base 2) of the field size in octets. The frame size is the smaller of the size indicated by the value of S105 and any restrictions imposed by the particular link layer protocol in use. Type (log[size]/log[2]) Value range 4 to 9, Default value: 8 Stored by &Wn yes Displayed by &V no Values Value Bytes ------------------- 4 16 5 32 6 64 7 128 8 256 9 512 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S108 - Signal Quality Selector ------------------------------------------------------------------------- Description This register only affects V.32 bis and V.FC connections. Register S108 sets the signal quality required for the modem to handshake at the highest designated speed and for automatic rate re-negotiation. If the modem determines during carrier handshake that the signal quality is less than that specified by S108, the modem attempts to connect at the next lower speed indicated by S109, unless the N0 command is selected. If the N0 command is selected, only the speed indicated by S37 may be used (during handshake). The signal quality (such as MSE) that corresponds to each S108 value depends on line speed. That is, larger MSE values should be used at lower line speeds. The appropriate measure of signal quality may be a function of modulation and coding used. The bit error rate (BER) values that correspond to S108 values are listed below. These BER values are determined for the modem with an average channel and Gaussian noise. Type value Value range 0-3, Default value: 1 Stored by &Wn yes Displayed by &V yes Values Value Bytes ------------------------------------------------- 0 no limit (10-2 BER) 1 low quality (i0-4 BER) 2 medium quality (10-5 BER) 3 high quality (10-6 BER) +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S109 - Carrier Speed Selector ----------------------------------------------------------------------------------------------------------------------------- Description Register S109 selects the speeds available for V.32, V.32 bis and V.FC carrier handshake, retrains, and rate re-negotiations. Register S37 selects the highest carrier speed that may be used during handshakes. If the N0 command is selected, the speed indicated by S37 and one of the speeds selected by S109 must match; the modem connects only at that speed. Register S37 and the N0 command do not affect the modem speed while in V.32 bis mode during a retrain or rate re-negotiation procedure. Note: When doing a V.32, V.32 bis, or V.FC handshake, the modem connects only at speeds enabled by S109. If Ans-A or Orig-A handshake behavior is selected (defined for Nn command) and the speed indicated by S37 is one of the set covered by S109, then the speed must match one of the speeds selected by S109 or when the modem enters the handshake process the modem sets S86 to value 16, hang-up, and sends NO CARRIER result code. If the speed selected by S37 is not one of those covered by S109, then the handshake proceeds normally. Type bit mapped, Default value 4094 Stored by &Wn yes Displayed by &V yes Bit Map Bit Value ---------------------------------- 0 Reserved 1 4800 bits/second 2 7200 3 9600 4 12000 5 14400 6 16800 7 19200 8 21600 9 24000 10 26400 11 28800 12 reserved 13 reserved 14 reserved 15 reserved +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S110 - V.32/V.32 bis Selector ------------------------------------------------------------------------- Description The V.32 and V.32 bis carrier handshake procedures are compatible. The rate sequence contains bit combinations that specify which procedure is used. Register S110 provides control of that selection for those who want to limit carrier handshake procedure to that specified by V.32 or to disable automatic rate re-negotiation (rate changes initiated by the modem based on signal quality). When the value of S110 is 0, the V.32 handshake procedure is followed, rate re-negotiation (which is allowed by V.32 bis) is disabled, and the &U command determines whether or not trellis coding is enabled. When the value of S110 is 1, the V.32 bis handshake is enabled, but not automatic re-negotiation. The modem responds to a rate re-negotiate request from the other end, but tells the other end that only the current speed is available. When the value of S110 is 2, V.32 bis both handshake and - automatic rate re-negotiation are enabled. Type value Range 0-2, Default value: 2 Stored by &Wn yes Displayed by &V yes Values Bit Value ------------------------------------------------- 0 V.32 enabled 1 V.32 bis enabled 2 V.32 bis and automatic rate re-negotiation enabled Note: V.32 bis enabled includes V.FC if supported by the modem. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S113 - Calling Tone Control ------------------------------------------------------------------------- Description The value in this register determines whether calling tone is transmitted during call origination. If calling tone is sent, it starts after dialing has been completed and continues until answer tone or carrier is detected from the answering modem. Calling tones comply with the requirements of V.25. Use of calling tone is regulated in certain countries. In countries where calling tone is required, S113 is not implemented in the modem. That is, if calling tone is turned on, then S113 always has value 1 and if the command S113=0 is sent, then the modem returns OK but does not change the value. Type value Value range 0-1, Default value: 0 Stored by &Wn yes Displayed by &V no Parameter Values 0 calling tone is not sent 1 calling tone is sent +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S121 - Use of DTR ------------------------------------------------------------------------- Description Register S121 selects how the time indicated by the value of S25 affects the recognition of changes in the state of DTR. The behavior defined for value 1 allows the modem to be used with a system that does not provide a DTR signal. Note: This feature is not supported in all OPTIMA and ACCURA products. Type value Value range 0-1, Default value: 0 Stored by &Wn yes Displayed by &V no Values 0 - Normal DTR state and state change behavior as defined by &Dn commands. 1 - If DTR is off, it is ignored (does not need to be on to maintain a connection). If DTR goes from off to on, it is ignored. If DTR goes from on to off, obey &Dn command. This value is not intended inhibit autoanswer. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S141 - Detection Phase Timer ------------------------------------------------------------------------- Description This register sets the V.42 detection phase timeout, T400, which determines how long a modem waits for an Originator Detection Pattern (ODP) or Answerer Detection Pattern (ADP) before abandoning its attempt to establish an error-correcting connection. The action to take if the error-correcting attempt is abandoned is determined by the value of S36. An originating modem waits for the time indicated by the value of S141 to detect an ADP pattern. An answering modem waits for the indicated time to detect the ODP pattern. If the answering modem receives ODP, then the answer modem sends the ADP pattern and waits for flags for up to twice the T400 time. If flags are not detected, then the modem hangs-up. Type value (centiseconds) Value range 10-255, Default value: 85 (850 ms) Stored by &Wn yes Displayed by &V no +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S142 - Online Character Format ----------------------------------------------------------------------------------------------------------------------------- Description S142 determines the DTE-DCE character format the modem uses while in the online state and using V.14, V.42, V.42bis, or ASB interface procedures. S142 does not affect the DTE-DCE character format when the modulation type is FSK and ASB is not in use. Type value Value range 0-5, Default value: 0 Stored by &Wn yes Displayed by &V yes Values Bit Online state character format ------------------------------------------------- 0 8N1 (this also covers all 7x1 formats) 1 8E1 2 8O1 3 8M1 (same as 8N2) 4 8S1 5 Format of last command. The effect of S142 depends on the DTE Interface protocol used, as described below. V.14 - The modem sends and receives characters in the selected format. This preserves parity bits during transmission. V.42 and V.42bis - The modem sends and receives octets as prescribed by V.42, and absorbs and generates parity bits of 11-bit characters locally. While this procedure does not transmit parity bits between DCEs, it does conform to V.42. ASB - The modem buffers octets but sends selected parity to other DCE, using V.14 procedure. The modem receives the selected parity from other DCE and passes it on to local DTE. This procedure passes parity bits between the DCEs and allows detection of line errors as parity errors. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S144 - Autobaud Speed Group Selection ----------------------------------------------------------------------------------------------------------------------------- Description Depending on your computer model and the year it was made, your modem supports a set of DTE speeds. For the highest possible DTE speed obtained through speed negotiation, select the value of S144 that best describes your computer. The default is for this S- register. is 0. Type value Value range 0-2, Default value: 0 Stored by &Wn yes Displayed by &V no Value Speeds 0 - Standard DTE Speed, Use S144 =0, if your computer is not an NEC PC-9800 series. S144=0 supports the following DTE speeds: 300, 600, 1200, 2400, 4800, 7200, 9600, 12000, 14400, 19200, 38400, and 57600 bits/second. Set 1 - DTE Speeds for NEC PC-9800 Series Computers, Use S144 =1, if your computer is an NEC PC-9800 series model which supports the following DTE speeds: 300, 600, 1200, 2400, 4800, 9600, 20800, 31200, 41600 and 62400 bits/second. Set 2 - DTE Speeds for NEC PC-9800 Series Computers, Use S144 =2, if your computer is an NEC PC-9800 series model which supports the following DTE speeds: 300, 600, 1200, 2400, 4800, 9600, 19200, 38400, and 51200 bits/second. As a general guideline, the DTE speeds designated as Set 1 are supported by NEC PC-9800 series models, manufactured prior to 1993. The DTE speeds designated as Set 2 are supported by NEC-9800 series models, manufactured during or after 1993. Refer to your computer's user documentation to determine which set your computer supports. Note: The speeds available with value 0 may be limited by selections made in the feature table. Note: The commands %Nx (x = 0,1,2) also set S144 to value x. ========================================================================= Chapter 7 Modem States ************************************************************************* Modem Functions Hayes modems provide auto dial and auto answer functions in addition to transmission and reception of data signals. The modem goes off hook, dials numbers, connects to a distant modem (handshakes), modulates data from a local DTE for transmission, and demodulates received signals from a distant modem. The modem also provides many auxiliary functions, including several types of tests. The AT command set facilitates control and observation of modem functions. ************************************************************************* Major States +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Idle State In the Idle State, the modem is not communicating with a distant end, and, if not in dumb mode, is ready to accept commands. The modem is usually on hook while in the Idle State, but may be off hook. The modem goes into the Idle State directly after it's powered-on. See Chapter 13. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Dialing State In the Dialing State the modem may be waiting for dial tone, sending dialing signals, pausing, or some other dialing operation. The modem enters the dialing state as a result of executing the D command. Refer to the Dialing Process in Chapter 8 for more information. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Handshaking State In the Handshaking State the modem may be sending answer tone, waiting for answer tone, or handshaking with another modem. The modem enters Handshaking State when one of the following occurs: * Dialing Process * Modem autoanswer * DTR OFF-to-ON transition when &Q3 is in effect * Power is turned on in the dumb leased-line mode. The handshaking process can be running in the originate mode or the answer mode. Refer to the &Dn command in Chapter 4 and the "Handshaking Process" in Chapter 8 for more information. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Online State In the Online State the modem sends and receives data with a distant modem. The modem may enter the Online State from the Handshaking State as a result of the Handshaking Process or from the Online Command State as a result of the On command. Signals from the DTE are treated as data and transmitted to the distant end. Refer to the O command in Chapter 4 and Online State in Chapter 8 for more information. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Online Command State In the Online Command State the modem will maintain the connection with the distant modem, but it treats DTE signals as commands. The modem may enter the Online Command State as a result of the Hayes Patented Escape Process with guard time or as a result of a DTR ON-to-OFF transition when certain combinations of &Dn and &Qn are in effect. The Online Command State only exists in the Smart Mode. Refer to the &Dn and &Qn commands in Chapter 4, and the "Hayes Patented Escape Process with guard time " and "Online Command State" in Chapter 8. ========================================================================= Chapter 8 Processes and Procedures This Chapter describes basic modem processes and procedures. ************************************************************************************************** Answering Process The answering process is used to answer a call. The process may be started by the A command, by turning DTR on, by the modem detecting a certain number of ring events, or by power going on in the dumb leased-line mode. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Entry Enter Answer Mode from Idle State if: * The A command is sent to the modem while &Q0, &Q1, or &Q4 is in effect. * A ring signal is detected, &Q0, &Q1, or &Q4 is in effect, S0>0, and S1>=S0. If &D2 is in effect, then DTR must also be ON. If DTR goes ON after the ring for which S1>=S0, then the answer process begins after the end of the next ring following the RING result code. * A ring signal is detected, &Q2 or &Q3 is in effect, S0>0, S1>=S0, and DTR goes on after the first ring. The answer process begins after the end of the ring for which S1>=S0 following the RING result code. If DTR goes ON after the ring for which S1>=S0, then the answer process begins after the end of the next ring following the RING result code. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Exit Exit the answering process as follows: * Exit to Handshaking state if Answering process is completed. * Exit to Hard Reset if &D3 and DTR go on-to-off. * Exit to hang-up process if: * Key press abort (if enabled by &Q command). Result code: NO CARRIER * &D2 and DTR goes on-to-off. Result code: OK * (&Q1 or &Q4) and &D0 and DTR go on-to-off. Result code: OK * (&Q2 or &Q3) and DTR go on-to-off Result code: OK +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Execution Time The steps listed below take a maximum of 10 ms to execute. (More time may be taken by the handshaking process.) +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process Steps * Set speaker volume according to Ln and Mn commands. * If &Q2 or &Q3 is in effect, turn off CTS. * If &Q1 or &Q4 is in effect, and S0>0, turn off CTS. * Go off hook. * Turn on OH LED. * Go to handshaking process, answer mode. ************************************************************************************************** Carrier Detection Carrier detection while the modem is in the online state is governed by the times specified by registers S9 and S10. The CD LED is the carrier detected indicator. If the carrier signal goes off, the CD LED goes off within 20 ms. If the carrier returns, the CD LED turns on within 20 ms after the carrier has been on continuously for the time specified by S9. If the carrier remains off for the time specified by S10, then the modem hangs up. If S10 is set to 255, the time is considered to be infinite; the modem does not hang up due to loss of carrier signal. Various algorithms may be used by a modem to detect carrier, in addition to estimating received signal power. When any of these algorithms indicate carrier is not being received, the S9 and S10 time intervals are used to determine when to clear the call. See also the &Cn command in Chapter 4 for RLSD behavior. ************************************************************************************************** Dialing Process The dialing process causes the modem to go off hook, wait for dial tone, and send the dial digits or execute the dial modifiers in the dial string. The process may be started by a command from the DTE, or by DTR going on while the &Q2 command is in effect. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Execution Time The dialing process requires the time to send the dialing signals and execute any dial modifiers. See the individual commands and dial modifiers for execution times. The modem enters the dialing process if: * D command is entered (if the command is valid) * &Q2 and DTR comes on and ringing has not been detected (i.e., S1=0) In this case, stored number 0 is dialed. The modem exits the dialing process as follows: * Hard Reset if &D3 and DTR go on-to-off. * Handshaking State if dialing process is completed. * Idle State if a semicolon dial modifier is executed. * Hang-up Process if: * Key press abort (not &Q2 or &Q3). Result code: NO CARRIER * (not &Q2 or &Q3) and &D2 and DTR go on-to-off Result code: OK * (&Q1 or &Q4) and &D0 and DTR go on-to-off Result code: OK * (&Q2 or &Q3) and (&D0 or &D1 or &D2) and DTR go on-to-off Result code: OK +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process Steps Step 1: If the modem is off hook, go to Step 11. Step 2: Set speaker volume according to Ln and Mn commands. Step 3: If &Q2 or &Q3 is in effect, turn off CTS. Step 4: If &Q1 or &Q4 is in effect, and S0>0, turn off CTS. Step 5: Go off hook and turn on OH LED. Step 6 : If &J1 is in effect, operate auxiliary relay. Step 7: If &L1 is in effect, go to handshaking process, originate mode. Note: Dial digits and dial modifiers are ignored in leased-line mode (&L1 in effect). Step 8: If &Q3 is in effect, go to handshaking process, originate mode. Step 9: If (X2 or X4) is in effect, then look for 1 second of dial tone within 5 seconds. If no dial tone in 5 seconds, go to hang-up process with NO DIALTONE result code. If dial tone is detected, proceed. Step 10 If X0, X1, or X3 is in effect, then wait for time indicated by S6, then proceed. This is blind dialing. Step 11: Do the following four steps until all of the dial digits and dial modifiers have been executed, then go to Step 12. (a) Examine next dial digit or dial modifier. (b) If a dial modifier, then execute. If the dial modifier is the semicolon then go to the idle state and continue execution of the command line. (c) If a dial digit and tone dialing, send DTMF tone with duration indicated by S11 and wait for time indicated by S11 before going on to next dial digit or modifier. (d) If a dial digit and pulse dialing, send the indicated number of pulses. Each pulse consists of opening the line relay (break) and closing the line relay (make) for the times determined by which &Pn command is in effect. Wait for interdigit delay time before going on to the next dial digit or dial modifier. Note: Dial digits A, B, C and D cannot be sent by dial pulses and are ignored. Step 12: If one of the dial modifiers was R, go to handshaking process, answer mode. Otherwise go to handshaking process, originate mode. ************************************************************************************************** Hayes Improved Escape Sequence with Guard Time The Hayes Improved Escape Sequence with Guard Time (U.S. Patent #4,549,302) is used when the modem is on-line and you need to enter commands to the modem without disconnecting. The escape sequence with guard time protects you against losing the connection while you are sending commands to your modem. A guard time must precede and follow the sequence of escape characters so that, should the same characters need to be transmitted in a message, the modem will not accidentally switch to command state. The default guard time is 1 second. The escape sequence character and the guard time interval can be changed by assigning different values to registers S2 (for the escape character) and S12 (for the guard time). To use the escape sequence with guard time: Step 1: Pause a little longer than the guard time. Step 2: Type +++. Step 3: Pause again a little longer than the guard time. (These pauses help the modem to distinguish the escape sequence from your message.) Step 4: Enter any necessary commands to the modem. Step 5: When you are ready to resume your call to a remote system, type ATO . The modem will return to the on-line state. ************************************************************************************************** Handshaking Process When the modem is sending answer tone, receiving answer tone, or handshaking with another modem, it is said to be in the handshaking state. The handshaking process can be run in either the originate or answer mode and is designed to follow both domestic (Industry Standard 103, 212A), international (e.g., ITU-T [formerly CCITT] recommendations), and proprietary procedures. In the originate mode, if X3 or X4 command is in effect, the modem will monitor for a busy signal after dialing. The handshaking process is timed twice by the time specified by register S7. If answer tone is not detected within the specified time after the handshake process starts, the process will exit to the hang up process. The timer is reset when answer tone is detected. If the modem does not finish handshaking with the distant end within the specified time, the modem exits to the hang up process. The line speed at which the modem will attempt to connect is determined by the Nn and Bn commands, the last AT speed, the value of S37, the selected &Q command, S108, S109, S110. If all of these have their default values, then the modems will attempt a line speed that is determined by their AT speeds according to the table below. If S37 is not zero, then S37 selects the maximum line speed. (Refer to the S37 definition for more details.) +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Execution Time The process either completes within twice the time specified by S7 or it aborts. Timing of answer tone transmission is determined by the applicable modem technical requirements. The process may abort; the time limits are discussed below. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Entry The modem enters the handshaking process if: * From dialing or answering processes. If &S1 is in effect, turns DSR on. * From Idle State by On command if off-hook. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Exit The modem exits from handshaking process to: * Hard Reset if &D3 is in effect and DTR goes on-to-off. * Online state if Handshaking is successful. Result code CONNECT. If &C1 is in effect, RLSD goes on after connect result code. * Hang up process if: * Answer tone is not detected within the time specified by S7; NO CARRIER result code. * If X3 or X4 is in effect and busy signal is detected before answer tone; BUSY result code. * Modem handshake is not completed in time specified by S7. Result code NO CARRIER. Note: Modem handshake time out begins after answer tone or carrier is detected and is a separate use of S7. * &Q2 or &Q3 and DTR goes on-to-off. Result code OK * (not &Q2 or &Q3) and key press abort. Result code: NO CARRIER * (not &Q2 or &Q3) and &D2 and DTR goes on-to-off Result code: OK * (&Q1 or &Q4) and &D0 and DTR goes on-to-off Result code: OK * (&Q2 or &Q3) and (&D0 or &D1 or &D2) and DTR goes on-to-off Result code: OK +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Process Steps Step 1: Start a timer at time specified by S7. If in originate mode, then go to Step 2. If in answer mode, go to Step 5. Step 2: If X3 or X4 is in effect and busy tone is detected, then exit to hang up process with BUSY result code. If answer tone or carrier is detected, then go to Step 3. If neither tone is detected before the timer times out, then exit to hang-up process with NO CARRIER result code. Step 3: Start a timer at time specified by S7. If carrier is detected, then turn on CD LED and go to Step 4. If carrier is not detected before the timer times out, then exit to hang-up process with NO CARRIER result code. Step 4: If &S1 is in effect, then turn on DSR. Continue with modem handshake. If modem handshake completes before the timer times out, then go to Step 7. Otherwise go to hang-up process with NO CARRIER result code. Step 5: Wait 2 seconds. If &S1 is in effect, then turn on DSR. Send answer tone. Start a timer at time specified by S7 and go to Step 6. Step 6: Turn on CD light and complete modem handshake after carrier is detected. Send CARRIER and PROTOCOL result codes (if enabled) after the carrier and protocol negotiations complete, go to Step 7. If timer times out before modem handshake is completed, then exit to hang-up process with NO CARRIER result code. Step 7: Send CONNECT result code and set response speed to equal the line speed. If &C1 is in effect, turn on RLSD. Go to online state. Notes: a) See the "Carrier Detection Process" and CD light behavior for details of CD LED operation. b) See RLSD lead behavior for details of its operation. c) Result codes passed to the hang-up process are sent to the DTE at the end of the process. d) The handshake process is restarted if the &L1 command is in effect and S7 times out. e) The following events aborts all handshake process steps: i) (&Q0, &Q1, or &Q4) and key press abort. Result code is NO CARRIER. ii) (&Q0 or &Q1 or &Q4) and &D2 and DTR goes on-to-off. Result code is OK. iii) (&Q1 or &Q4) and &D0 and DTR goes on-to-off. Result code is OK. iv) (&Q2 or &Q3) and (&D0 or &D1 or &D2) and DTR goes on-to-off. Result code is OK. v) Exit to Hard Reset if &D3 is in effect and DTR goes on-to-off. No result code. ************************************************************************ Hang-up Process The hang-up process readies the modem for the idle state. Result codes passed to the process are sent to the DTE at the end of the process. This process completes in 1.5 to 2 sec plus any processing time, which is implementation dependent. ************************************************************************ Resets There are several levels of reset, depending on what triggered the action. You can view the resets as the following sequence: (1) self test, (2) EEPROM tests, (3) read switch settings, (4) establish profile and other actions. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Power On Reset When the modem power is turned on, the reset process starts at Step 1, below. A hard reset, caused by DTR going off while &D3 is selected, starts the reset process at Step 2, below. The Z command starts the process at Step 3, below. At the end of a power on reset, the modem will have loaded the profile specified by the &Yn command. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Hard Reset A hard reset is initiated by DTR going on-to-off while &D3 is in effect. When a hard reset occurs, the modem performs the following actions: Step 1: Hangs up. Step 2: Turns on the HS and MR LEDs. Step 3: Copies into the active profile area the stored profile that is specified by the &Yn command. Step 3: The hard reset process ends with the modem going to the idle state, on hook. No result code is sent to the DTE. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Execution Time A hard reset shall be completed in 2 seconds or less as may be required by the product implementation. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Soft Reset The reset initiated by the Z command may be called a soft reset. See the command description of the actions started by the command. ************************************************************************* Key Press Abort Key Press Abort refers to the aborting of an answering, dialing, or handshake process as a result of the DTE sending any character to the EIA-232D interface of the modem. The modem recognizes and responds to any such received character within 500 ms and goes to the hang-up process. The result code depends on the process being aborted. Refer the "Dialing", "Answering", and "Handshaking Processes" sections in this Chapter. ************************************************************************* Online State The online state is the modem state wherein a modem is able to send and receive modulated data signals to and from a remote modem. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Entry Enter the Online State from O0 or O1 commands or from handshaking states. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Exit The modem exits to online command state if: Note: OPTIMA products support &Q1, &Q2 and &Q3. * Not (&Q1 or &Q2 or &Q3 or &Q4) and the Hayes Patented Escape Sequence with guard time completes. Result code is OK. * (&Q0 or &Q1 or &Q4) and &D1 and DTR goes on-to-off. Result code is OK. The modem exits to hang-up process state if: * (not &Q2 or &Q3) and &D2 and DTR goes on-to-off. Result code is OK. * (&Q1 or &Q4) and &D0 and DTR goes on-to-off. Result code is OK. * (&Q2 or &Q3) and (&D0 or &D1 or &D2) and DTR on-to-off. Result code is OK. * Carrier signal is lost. See "Carrier Detection". Result code is NO CARRIER. *********************************************************************** Online Command State The Online Command State is used to give the modem commands while holding a connection to the distant end. While in this state, data cannot be sent or received. The distant end receives continuous mark signal. Characters from the DTE are treated as commands. Received data patterns, RDL requests, and equalizer retrain requests from the distant end are honored while the modem is in the Online Command State. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Entry * Enter Online Command State from the online state if in Smart Mode, (not &Q2 or &Q3) is in effect, DTR goes ON-to-OFF, and DTR remains OFF for more than the time indicated by register S25. * Enter Online Command State from the online state if in Smart Mode, (not &Q2, &Q3, or &Q4) is in effect, and the Hayes Patented Escape Sequence with guard time is performed from the DTE at the Line Speed. Refer to "Hayes Patented Escape Sequence with guard time" in this Chapter. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Exit * Exit to Hard Reset if &D3 and DTR goes on-to-off. * Exit to online state if: * O command is entered. Result code is CONNECT. * O1 command is entered and retrain is successful. Result code is CONNECT. * Exit to idle state if: * O1 command is entered and retrain is not successful. Result code is NO CARRIER. * Exit to idle state if carrier is lost for the time specified by S10. Result code is NO CARRIER. * Exit to hang-up process if: * (not &Q2 or &Q3) and &D2 and DTR goes on-to-off. Result code is OK. * (&Q1 or &Q4) and &D0 and DTR goes on-to-off. Result code is OK. * (&Q2 or &Q3) and (&D0 or &D1 or &D2) and DTR goes on-to-off. Result code is OK. ************************************************************************ Response To Ringing +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ General The RI lead follows the presence of a ringing input. The S1 register value is incremented after the end of each ring detected. Unless result codes are inhibited by the Qn command or the modem is in the command editing or execution state, the RING result code is sent to the DTE after the end of each burst of power that is deemed to be a valid ring signal. Valid ring signal depends on country. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ RI Lead The RI lead is turned on immediately after ringing is detected and remains on until 600 ms of no ringing is detected. This means that short off intervals between ring-events are ignored. It also means that the ringing indications are stretched by 600 ms. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S1 Register. The S1 register is incremented immediately after the RI lead is turned off. S1 is reset after 8 seconds if S1 has not been incremented meanwhile. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ RING Result Code. The RING result code shall be issued after S1 is incremented. ************************************************************************ RDL Process If the modem is in the online state with &T4 in effect, then when it detects an RDL request from the distant end it sends the acknowledgment signal (defined in V.22 and V.22 bis) to the distant end and starts repeating all received data back to the distant end. The RDL process is said to be operating while the modem is repeating received data back to the distant end. Received data is not sent to the DTE and the MR light is flashed while the RDL process is operating. When the RDL termination signal is received from the distant end, the modem acknowledges the signal and returns to normal online operation. Because the RDL requester is in the Online Command State, that modem may also accept any commands that are otherwise valid in that context, including the &T0 command that terminates the RDL process. Because the grantor is in the online state, that modem also responds to the Hayes Patented Escape Sequence with guard time, thereby allowing that modem to issue the &T0 or other command. Timing of remote digital request and acknowledgment signals is specified in ITU-T V.22. ========================================================================= Chapter 9 FAX Functions ************************************************************************* Introduction Group 3 facsimile (FAX) service, based on ITU-T recommendations T.4 and T.30 [2,4], is widespread. Note: References are listed at the end of this chapter. Hayes modems may include Group 3 FAX capability. Control of FAX modems is by means of the DTE to DCE interface specifications for modems, known as Class 1[1]. Class 1 provides a set of primitive commands and result codes [1]. The DTE must provide T.30 session management and T.4 image handling. This Chapter contains specifications for the features and performance of Hayes facsimile modems based on Class 1 interface commands and responses. New commands, S-registers, and result codes for FAX are included. This Chapter describes how the functions work; not which functions are included in particular products. Individual product requirements need to indicate which functions are required for products. ************************************************************************* Philosophy The modem provides a separation of data and FAX commands. In particular, data commands that affect the definition of certain characters (S3, S4, etc.), determine how many rings to detect before automatic answering (S0), and set the response behavior (E, Q, and V) which affect both FAX and data behavior. All other commands that determine the modem behavior while on line apply only to data calls. The FAX command +FCLASS determines whether the modem is currently in the data or FAX mode. The behavior of DTE Interface control leads and lamps while the modem is in a FAX mode is the same as when in the data mode. That is, there is no special behavior for the FAX modes. Data and FAX parameters are stored, loaded, and reset as follows: * The &F command restores Factory Default values of all data and FAX parameters. * The Zn commands clear any call, load the appropriate set of data parameters, and set +FCLASS = 0. The Zn commands do not change any other FAX parameters. * The &Wn commands store data parameters. FAX parameters are not stored; most FAX programs send FAX parameters to a modem before using the modem for a call. The modem is in data mode when +FCLASS equals 0, the default value for this parameter. When the value of +FCLASS is 1 the modem is in a FAX mode. ************************************************************************* Modem FAX Modes As mentioned above, a modem may be used in one of three modes: * smart AT * switched smart * switched Dumb. Note: OPTIMA products support the switched Dumb Mode feature. The FAX mode is a subset of the smart AT, switched mode of operation. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ FAX Class 1 Mode When the value of the parameter +FCLASS is 1, the modem is in the FAX Class 1 mode. In this mode all data commands, plus the commands, behavior, and responses defined in [1] are valid. ************************************************************************* DTE Interface Leads The following circuits are required. * Signal ground * Transmitted data * Received data. The following circuits are optional. * Request to send (for flow control) * Clear to send * Data terminal ready * Received line signal detector * Ring indication. Hayes modems provide the usual DTE Interface leads, which include the required and optional leads listed above. ************************************************************************* General FAX Operation +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ FAX Commands and Responses All FAX messages have the prefix +F. The three types of messages are action commands, responses, and parameters. Commands are sent from the DTE to the DCE. Responses are messages from the DCE to the DTE. Parameter values may be passed in either direction. The DTE may set values; the DCE may report Values. Parameters are assigned values by commands of the form +FPARM=value, where PARM means any parameter name. Current parameter values can be read by the DTE using commands of the form +FPARM?. The DCE responds with a string of values or lines of information text. The +FCLASS parameter sets the basic mode of the modem as mentioned above. The parameter values are: +FCLASS Meaning ---------------------------------- 0 data mode 1 FAX Class 1 The +F parameters may be changed while the modem is in data mode and off line. Invalid FAX commands and FAX commands that cannot be executed cause an ERROR result code. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ FAX Identification Responses The +FMI? command invokes the following information text. Hayes Microcomputer Products, Inc. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ FAX Commands in Data Mode The only Class 1 command that is valid in data mode is +FCLASS. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Escape From On-line State The FAX commands always return to command state after execution. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ DTE Interface Speed FAX Class 1 requires the DTE Interface speed to exceed the line speed. See [1] 5.3 for details. Bi-directional flow control is used to regulate the flow of data between the DTE and the DCE (modem). ************************************************************************ FAX Class 1 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ General A FAX Class 1 DCE can establish calls, and can send and receive data strings using one of several modulation and protocols. The DTE must prepare all transmitted character strings and analyze all received data strings. The DCE handles flags and frame check sequences when such are required. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Commands All of the Class 1 commands and responses defined in [1] are implemented in Hayes FAX Class 1 modems. Reference 1 includes V.17 and other modulations. If the modem does not provide a modulation, then the modem returns the ERROR result code to any command that invokes the missing modulation. The value of register S86 is set to 1 if a hang-up occurs while the modem is in the FAX mode. FAX Class 1 action commands are valid only while the modem is off hook. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Answer Handshake A Class 1 modem provides limited handshake capability. The modem goes off hook and sends the V.21 signals specified in [1]. Answering may be initiated by the A command or by the value of S0 exceeding 1 and ringing being detected by the modem. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ FAE Automatic Data/FAX Handshake Description When the modem is configured for Class 1 operation (+FCLASS=1), the +FAE command may be used to invoke automatic determination of data or FAX incoming calls, and use of the DATA and FAX result codes. The +FAE command is valid for all +FCLASS values, but affect modem behavior only when +FCLASS=1. If +FAE=0, then incoming calls must be answered by DTE commands and the modem do not use the FAX or DATA result codes. If +FAE=1 and the modem answers a call, the type of calling station may be determined by detection of calling tone or by probing during handshake. If it is determined that the calling station is a FAX machine or modem, then the answering modem sends flag idle signal (V.21 modulation) and sends the FAX result code to the DTE. The DTE then sends the appropriate Class 1 commands to the modem to complete the call. If it is determined that the calling station is a data modem, the answering modem completes the handshake, set +FCLASS=0, sends the DATA result code to the DTE, and then sends the normal data call result codes to the DTE to complete the call setup. If +FAE=1, then the silent period after an answer modem goes off hook is 4 seconds instead of the usual 2 seconds. This allows time to detect a FAX calling tone before sending answer tone. +FAE is reset to value 0 when a Z or &F command is executed. Type parameter command Value range 0,1, Default value: 0 Stored by &Wn no Displayed by &V no Values +FAE=0 DATA/FAX discrimination disabled. +FAE=1 DATA/FAX discrimination enabled. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Result Codes Reference [1] names the following result codes, which can be used in numeric or verbose format. Numeric Verbose Meaning ------------------------------------------------------------------------- 0 OK Ready for another command. 1 CONNECT The modem is entering the data transfer state. 3 NO CARRIER The modem is ready for a command; the modem may not be on hook. 4 ERROR Last command could not be executed; modem is ready for another command. The connect result code is always CONNECT without regard for the modulation speed, which is selected by the DTE. All other modem commands and result codes are allowed. If the DCE detects a received tone different from that specified by a +FRM or +FRH command, the DCE sends the result code +FCERROR to the DTE and returns to command state. The numeric equivalent to +FCERROR is +F4. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Flow Control Local DC1, DC3 flow control is always enabled if +FCLASS=1 and the modem has a call established. In addition, if RTS is on when the command +FCLASS=1 is issued, then RTS/CTS flow control is also invoked. This procedure for managing flow control is used because FAX Class 1 specifies the use of DC1, DC3 flow control and allows other mechanisms, but does not make any provision for selecting flow control. FAX Class 1 software does not use the &Kn commands. ************************************************************************* Data Commands and Registers +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Commands The &F command sets all data and FAX parameters to their Factory Default Values. The only parameter for Class 1 is +FCLASS; its default value is 0. You must set +FCLASS=1 to enable Fax Class 1 mode. The Zn commands load the appropriate set of data parameters and do not change any FAX parameters. The &Wn commands store data parameters. FAX parameters are not stored; most FAX programs send FAX parameters to a modem before using the modem for a call. All data commands (the commands that do not begin with +F) are valid when the modem is in either data or FAX mode. However, the following data configuration commands affect only the data mode. Bn Cn Nn Yn &Bn &Gn &Mn &On &Qn &Rn &Un &Xn When the modem is in the FAX mode (+FCLASS=1), the &Cn command invokes the RLSD behavior associated with the &Q5 command. The Mn command determines when the speaker is turned on and off. When in the FAX mode, on until carrier means on until the initial CONNECT result code for Class 1. The speaker is actually turned off within 5 ms before or after the response is sent. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Special Call Setup Conditions Leased Line - FAX modem operation on leased lines is not supported. Reverse Modes - The &A command and R dial modifier are valid for FAX calls. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ S-registers The following S-registers do not affect the modem behavior while in the FAX mode. S18 S26 S30 S36 S37 S44 S45 S46 S48 S49 S50 S53 S55 S57 S69-S82 S84 S93 S94 S95 Register S47 is set to 0 when the modem is online in the FAX mode. The register normally indicates the type of data connection that has been established. Register S85 is set to 0 after a FAX call has been established. Register S86 is set to 1 if a hangup occurs while the modem is in the FAX mode. The value 1 is a new value for S86. The modem does not accept V.25bis commands while in the FAX mode. Since selection of the FAX mode requires use of an AT command, the modem has to be in AT command mode before issuing the +FCLASS=1 command. The HS light is on while the modem is in the FAX mode. The SD and RD lights indicate DTE Interface activity, as they do in the data mode. ************************************************************************************************** References 1. "Asynchronous Facsimile DCE Control Standard (Class 1)", document ANSI\EIA\TIA-578-1990. 2. "Standardization of Group 3 Facsimile Apparatus for Document Transmission", CCITT Recommendation T.4, 1984. 3. "Facsimile Coding Schemes and Coding Control Functions for Group 4 Facsimile Apparatus", CCITT Recommendation T.6, 1988. 4. "Procedures for Document Facsimile Transmission in the General Switched Telephone Network", CCITT Recommendation T.30, 1984. ========================================================================= Chapter 10 Dumb Mode ************************************************************************* General A modem is often used in dumb mode to support specific applications, especially synchronous applications, where the modem is powered-up and utilized without asynchronous DTE equipment for control. The modem is first configured in the Smart Mode using commands which are then stored in a profile by the &Wn command. ************************************************************************* Dumb Mode Characteristics Dumb mode observes the following characteristics: 1. The modem ignores all AT Commands. 2. Keypress abort is disabled. 3. Escape Sequences are ignored. 4. Result Codes, Info-text, and any other non-user-data are suppressed. 5. The CTS signal is not controlled by previous &Rn settings, but rather, operates more closely to the Industry Standard and ITU-T specifications for dumb modems as follows: a. CTS is OFF until the modem is ready to pass user data. CTS then goes ON, and stays ON until the modem goes back on-hook. Exception: CTS is off during retrain and rate re-negotiation. b. In Synchronous modes, the CTS signal follows the state of RTS. See also S26 for a definition of the amount of delay between RTS and CTS. c. In Asynchronous modes, CTS is not affected by RTS. d. CTS is not affected by local or remote loopback test states, except to be off during retrain and rate re-negotiation. 6. There is not an Online Command State. 7. See &Dn description for dumb mode response to changes in state of DTR. ************************************************************************* Making Calls The modem answers calls while in dumb mode according to which &Qn command is in effect and if register S0 was set to a non-zero value (before entering dumb mode). Note: Only OPTIMA modmes support dumb mode operation. The modem originates calls when DTR goes ON if &Q2 has been selected, by dialing the number associated with &Z0. The modem goes off hook and starts originate handshake when DTR goes ON if &Q3 has been selected. ************************************************************************ The Dumb Strap You have movable jumpers or a DIP switch to select whether the modem powers-up in Smart Mode or in Dumb Mode. The modem determines the mode during a power up or reset. Note: Only OPTIMA modems have a dumb strap. Whenever the traditional Hayes Smartmodem enclosure design is used to house a modem controlled by this specification, you are able to detach the modem front cover and adjust the position of the dumb strap. Refer to your modem's User Guide for the method to select this feature. ========================================================================= Chapter 11 DTE Interface ************************************************************************* General The pin numbers mentioned below are for the 25-pin interface connector. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Clock Leads (pins 15, 17, 24) Note: The Clock lead is available in OPTIMA products. Transmit signal element timing (pin 15) and receive signal element timing (pin 17) provide timing information to the DTE. Both leads are OFF (marking state) unless &Q1-&Q3 is in effect and the modem is in the Online or Online Command State. If &Q1-&Q3 and &X1 are in effect, the transmit clock (pin 24) from the DTE provides the transmit clock source while the modem is in the Online or Online Command State. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Clear to Send (CTS) - pin 5 Clear To Send indicates that the modem is ready to accept data from the DTE for transmission to the remote modem. If an OPTIMA modem is in the Dumb Mode, CTS is OFF in all states except online state and comes ON at the end of the handshaking process. If the modem is in the Smart Mode, CTS follows the rules described below: * In the Idle, On-Line Command, and Analog Loopback States, CTS is ON. * In the Dialing and Handshaking States, and during the Answer Process: * CTS is ON if &Q0, &Q5, or &Q6 is in effect. * CTS is OFF if &Q2 or &Q3 is in effect. * If &Q1 or &Q4 is in effect, CTS is OFF if S0 is not zero and ON if S0 is zero. * In the on-line state: * If &Q0 is in effect, CTS is ON. * If &Q1 is in effect, CTS goes OFF when the online state is entered for the time specified by S25 (in seconds). Then CTS goes ON if &R1 is in effect and tracks RTS if &R0 is in effect. * If &Q2 or &Q3 is in effect, CTS is ON if &R1 is in effect and tracks RTS if &R0 is in effect. * If &Q4 is in effect CTS goes OFF for the time specified by S25 (in seconds) when the online state is entered. Then CTS follows the Hayes AutoSync specification. Refer to the AutoSync specification 100-00085 for more information. * CTS goes OFF if carrier is lost from the remote modem and &Q1-&Q4 is in effect. It comes ON again when carrier is recovered if &R1 is in effect, or once RTS comes ON if &R0 is in effect. * If &Q5 or &Q6 is in effect, CTS is ON unless used for hardware flow control, which is selected by &K3. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Data Set Ready (DSR) - pin 6 Data Set Ready is an indicator of modem status to the DTE. The &Sn commands select the behavior of DSR, except if the modem is operating in one of the synchronous modes or in AutoSync mode. If &Q1-&Q4 is in effect, DSR acts as if &S1 is in effect regardless of the actual setting. DSR goes off if CD light goes off. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Data Terminal Ready (DTR) - pin 20 Data Terminal Ready is used for both call initiation, call termination, suppressing Autoanswer, and initiating a hard reset. The modem's actual response to DTR or a change in DTR depends on the &Dn and &Qn commands in effect and may also depend on S25 and S94. Some modem functions are affected by the level of DTR, while other functions may be affected by a transition in DTR. Also, DTR may affect the TR indicator. In addition to the information below, consult the &Dn and &Qn commands. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ High Speed (HS) - pins 12 and 23 The High Speed leads both indicate the same state as the HS light. In the Online Command or Idle States, HS is ON when the AT Speed is greater than or equal to 4800 bits/second, and is off otherwise. In the online state, HS is ON when the Line Speed is greater than or equal to 4800 bits/second, and is OFF otherwise. In the Handshaking State, HS may change after the CONNECT result code is sent to the DTE. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Receive Data (RD) - pin 3 The received data lead conveys data from the modem to the DTE. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Ring Indicator (RI) - pin 22 Ring Indicator indicates the presence of a ringing signal on the telephone line. When the modem is off hook or in an analog loopback test (&T1 or &T8), RI is off. If the modem is in the idle state and a valid ring signal is detected, RI comes on within 300 ms after initial signal detection and remains on until no more than 50 ms after the signal stops. If &Q4 (Hayes AutoSync) is in effect, and the online state is active, RI goes off when the end of frame byte has been transmitted and the transmitter is entering the idle state. RI goes high when the DTE (application) sends the next byte of data to the modem. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Received Line Signal Detector (RLSD) - pin 8 Received Line Signal Detector (RLSD) indicates the state of the remote modem's received carrier according to the &Cn and &Qn commands in effect. Refer to &Cn command definition in Chapter 4. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Request to Send (RTS) - pin 4 Request to Send, used to condition the modem for data transmission, is ignored when the modem is in online command, idle, dialing, or handshaking state. Once handshaking is complete and the online state is reached, RTS is tracked (except during carrier recovery) and only if &Q1-&Q3 is in effect, and &R0 is in effect. If RTS goes on, CTS is turned on after the time delay specified by S26 (in 1/100 seconds) plus a maximum of 10 ms. If RTS goes off, CTS is turned off immediately, plus a maximum of 10 ms. If &Q4 (Hayes AutoSync) is supported and in effect, and the modem is in the on-line state, RTS is used to force the modem receiver to reset and go into hunt mode. This is used in bisync (BSC) mode when the application detects the end of frame. RTS is ignored by the modem if one of the asynchronous DTE Interface modes is selected (e.g., &Q0, &Q5, or &Q6). +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Send Data (SD) - pin 2 The send data lead conveys data from the DTE to the modem. ========================================================================= Chapter 12 Modem LEDs The information in this Chapter applies to Hayes external modems. ************************************************************************* AA - Auto Answer AA indicates the states of S-register S0 and the ringer detector system. If S0=0, AA will be OFF while the absence of a ringer signal is detected, and AA will be ON while a valid ringer signal is being detected. If S0>0, AA is ON when no ring signal is detected, and AA is OFF while a valid ringer signal has been detected. Refer to "Ring Indicator" in Chapter 11. ************************************************************************* CD - Carrier Detection CD indicates the state of the modem's carrier detector system. CD is off in the idle state. In the handshaking state, CD comes on after the CONNECT result code is sent to the DTE. Once the online state is entered, CD tracks detected carrier within 20 ms (LED ON means carrier power detected). CD is not affected by the value of S9 or the &Cn command. Refer to "Carrier Detection" in Chapter 8. ************************************************************************* HS - High Speed HS and the HS leads of the DTE Interface (pins 12 and 23) indicate the same state. In the Online Command or Idle States, HS is ON when the AT Speed is greater than or equal to 4800 bits/second, and is off otherwise. In the online state, HS is ON when the line speed is greater than or equal to 4800 bits/second, and is OFF otherwise. In the Handshaking State, HS may change after the CONNECT result code is sent to the DTE. ************************************************************************* MR - Modem Ready MR indicates if a power up test fails or if a self test is currently active. On power up, if the RAM read/write test fails, MR goes OFF and the modem stops further activity. If RAM passes but the computed PROM checksum is incorrect, MR attempts to flash at a rate of 853 ms ON, 853 ms OFF (+10%) while preventing additional activity. If both tests pass, MR remains ON. When a self test (&T1, &T3, &T6-&T8) is running, MR also flashes at the above rate until the test is terminated and while the RDL process is operating. *************************************************************************** OH - Off Hook OH shows the state of the line relay. OH is off while the modem is on hook. *************************************************************************** RD - Receive Data RD represents the serial data sent to the DTE from the modem over the RD line (pin 3). RD is off when the signal represents a mark. *************************************************************************** SD - Send Data SD represents the serial data sent to the modem from the DTE over the TD line (pin 2). SD tracks the signal on Pin 2 of the DTE Interface within 1 ms. A mark signal on Pin 2 corresponds to the LED being off and SD is off when the DTE is not sending characters to the modem. ************************************************************************* TR - Terminal Ready TR indicates the state of the DTR line (pin 20). If &Q0 and &D0 are in effect, TR remains on regardless of the state of DTR. Otherwise, TR tracks the state of DTR. In the Idle State or Online Command State, TR tracks DTR within 50 ms. While in the Online State, tracking is within 10 ms. ========================================================================= Chapter 13 Relays This chapter describes modem relay functionality. ************************************************************************* Line The line relay is used to switch the modem on or off the telephone line. When the relay contacts are closed, the modem is off hook. Otherwise it is on hook. During pulse dialing, the line relay switches between the open and closed states at a rate in effect by the &Pn option (select make/break ratio). ************************************************************************* Phone The phone relay is used to switch the modem's phone jack on or off the telephone line. The relay contacts are closed while the modem is on hook; opened while off hook.