The following information is taken directly from the Gateway 2000 Telepath Data/Fax Modem User's Guide, part #070-00805, which is a publication that is protected by copyright and all rights are reserved. No part of it may be modified in any way, and distributions of this file must contain the complete unedited content. The information in this file has been carefully checked and is believed to be accurate. However, Gateway 2000 assumes no responsibility for any inaccuracies that may be contained in this document. In no event will Gateway 2000 be liable for direct, indirect, special, incidental, or consequential damages resulting from any defect or ommission in this document. In the interest of continued product development, Gateway 2000 reserves the right to make improvements in this document and the products it describes at any time, without notice or obligation. OK, enough of the small print... what you will find contained in the rest of this document is the set of AT commands and S registers that apply to the Telepath, along with reasonably complete descriptions of each. We left the fax portion for another time, assuming that this is what you really need for now. ------------------------------------------------------------------------ AT Commands ----------- Command Title Default ------- ------------------------------- ---------- A/ Re-execute Command none ATA Answer none ATBn Set CCITT or Bell Mode 1 (US)* ATCn Carrier Control 1 ATDn Dial P ATE Command Echo 1 * ATFn On-Line State Character Echo 1 * ATHn Switch-Hook Control none ATIn Indentification none ATLn Speaker Volume 2 * ATMn Speaker Control 1 * ATNn Modulation Handshake 1 * ATOn Return to the On-Line State none ATP Set Pulse Dial as Default none * ATQn Result Code Display 0 * ATSn? Reading S Registers none ATSn=x Writing to S Registers none ATT Set Tone Dial as Default none * ATVn Result Code Form (Message Control) 1 * ATWn Negotiation Progress Reporting 0 * ATXn Extended Result Codes 4 * ATYn Control Long Space Disconnect 0 * ATZn Reset none AT&Cn DCD Option 0 * AT&Dn DTR Option 0 * AT&F Restore Factory Configuration none AT&Gn Set Guard Tone 0 * AT&Jn Telephone Jack Selection 0 * AT&Kn DTE/Modem Flow Control 3 * AT&Ln Line Type 0 * AT&Mn Communication Mode (&Qn)* AT&Pn Dial Pulse Ratio 0 (US) * 2 (Japan) AT&Qn Communication Mode 5 * AT&Rn RTS/CTS Option 0 * AT&Sn DSR Option 0 * AT&Tn Test and Diagnostics 4 * AT&V View Current Config and User Profil none AT&Wn Store User Profile none AT&Xn Clock Source Selection 0 * AT&Yn Designate Default User Profile 0 * AT&Zn=x Store Phone Number none AT\An Maximum MNP Block Size 2 AT\Bn Transmit Break 3 AT\E Optimize Echo Cancellation none AT\Gn Modem to Modem Flow Control 0 AT\Kn Break Control 5 AT\Ln MNP Block Transfer Control 0 AT\Nn Operation Mode Control 3 AT\O Originate Reliable Link Control none AT\Tn Inactivity Timer Control 0 * AT\U Accept Reliable Mode Control none AT\Y Switch to Reliable Mode none AT\Z Switch to Normal Mode none AT%Cn Compression Control 1 * AT%Dn Set Dictionary Size (V.42bis) 2 AT%En Enable/Disable Auto Retrain 0 AT%L Report received Signal Level none AT%Mn Set One/Two-Way Mode (V.42bis) 3 AT%P Clear V.42 bis Encoder dictionary none AT%Q Report Line Signal Quality none AT%Sn Set Maximum String Length (V.42bis) 32 * Command may be stored in one of two users profiles with the AT&Wn command ----------------------------------------------------------------------- A/ -- Re-execute Command. Re-executes the most recent AT command string. The principal application of this command is to place another call (ie. Dial command) that failed to connect due to a busy line, no answer, or a wrong number. This command must appear alone on a command line and must be terminated by the "/" character. (A should not be entered to terminate the command.) ATA -- Answer. This must be the last command entered into the command line. The modem proceeds with the connect sequence in answer mode. The modem will enter the connect state after exchanging carrier with the remote modem. If no carrier is detected within a wait period specified in register S7 (default=50 seconds), the modem will disconnect. Any character may be entered via the DTE during the connect sequence to abort the command. Parameters: None Result Codes: CONNECT XXXX If a connection is established (XXXX = telco line for example, 2400). NO CARRIER If a connection cannot be established, the abort timer (register S7) expires, or if the command is aborted. ERROR If in data mode. ATBn -- Set CCITT or Bell Mode. Selects between CCITT and Bell Modes for 1200 and 300 bps. This command is not valid when the ATN1 command (automode detection enabled) is in effect. Parameters: 0,1 Default: 1 Result codes: OK for all valid parameters ERROR otherwise Command options: ATB0 = Selects CCITT V.22 and V.21 standards for communications at 1200 and 300 bps. ATB1 = Selects Bell 212A and 103 standards for communication at 1200 and 300 bps. ATCn -- Carrier Control. Controls the transmit carrier. The modem is preset to turn carrier on and off as necessary (the C1 option). The signal is on when the modem is calling, answering, or connected to a remote modem, and is off when it is not. The C0 option is NOT valid. Parameters: 0,1 Default: 1 Result Codes: OK for 1. ERROR otherwise. Command options: ATC0 = Not permitted;returns ERROR result code ATC1 = Normal transmit carrier switching (preset). ATDn -- Dial. This must be the last command on the command line. ATD causes the modem to go off-hook, dial according to the parameters entered, and attempt to establish a connection. If there are no parameters, the modem goes off-hook in originate mode without dialing a number. Punctuation may be used for clarity. Parentheses, hyphens and spaces are ignored. The modem truncates dial strings to 40 characters. Parameters: 0-9 A B C D * L P T R ! @ W , ; ^ S=n Default: P Result Codes: OK If ";" dial modifier is used. OK If key press abort during dialing process. NO DIALTONE If ATX2 or ATX4 is selected and 1 second of dial tone is not detected within 5 seconds; or if W dial modifier is used and 3 seconds of dial tone is not detected within the time specified by S7. BUSY If busy is detected, and ATX3 or ATX4 is selected or if W dial modifier is used. NO ANSWER If "@" dial modifier is used and 5 seconds of silence is not detected within the time specified by S7. CONNECT XXXX If a connection is established NO CARRIER If a connection cannot be established, the abort timer (register S7) expires, or a character is entered during the handshake process. ERROR If in data mode. The ATD Parameters are: L - Dials the last dial string that was dialed. P - Use Pulse Dialing. Placed at the end of the command string and before the dial string. Causes the modem to pulse dial the numbers. T - Use DTMF Dialing. Placed at the end of the command string and before the dial string. Causes the modem to use DTMF tones to dial. R - Reverse mode. Allows the modem to call an originate-only modem by forcing the call into "answer-mode". Must be entered as the last character of the command string (just before the ). ! - Hookflask. Causes the modem to go on-hook for 700 milliseconds and then off-hook. @ - Causes the modem to listen for 5 seconds of silence. If a 5 second silence has not been detected within the period specified in S7 (default=50 seconds), the modem disconnects and returns the 'NO ANSWER' result code. If it detects a busy signal, it returns a 'BUSY' result code. If the 5 seconds of silence is detected, then the modem continues dialing the dial string. W - Wait for Dial Tone Before Dialing. Causes the modem to wait for a dial tone up to the period of time specified in register S7 (default=50 seconds) before dialing the numbers that follow. If the modem detects a dial tone before the given time delay, it continues to dial. Otherwise, it goes on-hook. ' - Pause During Dial. Inserted between digits in a dial string. Causes the modem to pause for the value given by register S8 (default=2 seconds), before dialing the next digit. This delay can be used in place of the "Wait For Dial Tone Before Dialing". ; - Return to Command Mode after Dialing. Added to the end of the dial string. Causes the modem to remain in command mode after it dials the digits preceding the commands. This allows the user to issue additional dial command or dial strings without overflowing the command buffer. The modem looks for the carrier after the final dial command is issued. "ATHn" aborts this command. ^ - Turn on Calling Tone. Turns on the periodic 1300 Hz calling tone if originating the call. Calling tone is enabled only on a call-by-call basis. S=n - Dial Stored Number. Follows the dial command string. Causes the modem to dial a telephone number previously stored in directory location n using AT&Zn command. If "ATD" is entered without parameters, the modem goes off-hook and waits for carrier; if the handshake is not completed within the period of time specified by register S7 (default=50 seconds) the modem goes on-hook. The ATD command will be aborted in progress upon receipt of any character from the DTE before completion of hte handshake. ATE -- Command Echo. Controlst the echo of characters received by the modem from the local DTE while the modem is in command mode. Parameters: 0,1 Default: 1 Result Codes: OK for 0 and 1 ERROR otherwise Command options: ATE0 = Inhibits the echoing of commands ATE1 = Enables the echoing of commands ATFn -- On-Line State Character Echo. Determinesif the modem will echo data from the DTE. The modem does not support the ATF0 command. However, the modem will accept ATF1, which may be issued by some communication software packages. Parameters: n= 0,1 Default: 1 Result Codes: OK for 1 ERROR otherwise Command options: ATF0 = Error ATF1 = Disables on-line echo ATHn -- Switch-Hook Control. Applies to asynchronous operation only. If the user enter the command mode from the data mode by issuing the escape sequence (+++), or as a result of an ON-to-OFF transition of DTR with the AT&D1 option in effect, the user may cause the modem to go on-hook (disconnect) by issuing the ATH command. Parameters: n= 0,1 Default: none Result codes: OK for 0 and 1 ERROR otherwise Command options: ATH0 = Causes the modem to go on-hook (hang-up) ATH1 = If modem is on-hook, modem goes off-hook, returns an OK response, and awaits further commands. ATIn -- Identification. Returns the product code, returns the checksum of the firmware ROM, or computes the checksum of the firmware ROM and reports it's error status. The product code contains 3 digits. The checksum results consists of 3 ASCII numeric characters followed by a carriage return and a line feed. The error status is either OK or ERROR. Parameters: n= 0-2 Result codes: OK Default: none Command options: ATI0 = Reports the product code. ATI1 = Reports the checksum computed in the firmware ROM. ATI2 = Performs a checksum on the firmware ROM and indicates OK or ERROR. ATI3 = Reports firmware revision level. ATI4 = Reports product capabilities. ATLn -- Speaker Volume. Controls the internal speaker volume Parameters: n= 0-3 Default: 2 Result codes: OK for 0 to 3 ERROR otherwise Command options: ATL0 = Turns off speaker ATL1 = Selects low speaker volume. ATL2 = Selects medium speaker volume. ATL3 = Selects high speaker volume. ATMn -- Speaker Control. Controls the internal speaker while the modem is receiving a carrier signal or dialing. This command also enables or disables the speaker. Parameters: n= 0-3 Default: 1 Result codes: OK for 0 to 3 ERROR otherwise Command options: ATM0 = Speaker is always off. ATM1 = Speaker is on in handshake during call establishment but it's turned off while the modem is receiving a carrier signal from a remote modem. ATM2 = Speaker is always on. ATM3 = Speaker goes off while the modem is receiving a carrier signal from a remote modem and while the modem is dialing. However, speaker is on during answering. ATNn -- Modulation Handshake. This command can be used to assure that a connection is made only at the specified speed. If leased line is selected, this command is ignored and the modem operates as if ATN0 were selected. Parameters: 0,1 Result codes: OK for 0 and 1 ERROR otherwise Command options: ATN0 = Requires that the speed of the connection be specified by the value held in S37; If S37=0, the speedpf the connection must matchthat at which the last AT command was issued. If the selected speed can be achievedusing more than one communication standard (Bell 212A, CCITT V.22 at 1200 bps, and so forth), the modem also references the selection made with the ATB command. ATN1 = Permits handshaking to occur at any speed supported by both modems. Enables automode detection. The ATB command is ignored in this mode and the modem attempts only CCITT mode connections. ATOn -- Return To The On-Line State. Applies to asynchronous operation only. If the user enters the command mode from the data mode by issuing the escape sequence, or as a result of an ON-to-OFF transition of DTR with the AT&D1 option in effect, the user may return to the data mode without terminating the call by issuing the ATO command. This command may also be used to force a retrain. If the modem is on-hook, then the modem behaves as if it went off-hook to originate without actually taking the relay off-hook. Parameters: 0,1 Default: none Result codes: ERROR If &T1, &T3, or &T6-&T8 is active. CONNECT XXXX If a connection is established. NO CARRIER If retrain is not sucessful in the time specified by S7. Command options: ATO0 = Causes the modem to return to the data mode. ATO1 = Causes the modem to return to the data mode and to initiate a retrain when operating at 2400 bps. ATP -- Set Pulse Dial as Default. Causes the modem to assume that all subsequent dial commands are pulse dialed. The user may omit the "P" from the dial strings. Parameters: none Default: none Result codes: OK If issued outside dial string. ATQn -- Result Code Display. Determines whether or not the modem sends the result codes to the DTE (SeeATXn command). Parameters: n= 0,1,2 Default: 0 Result codes: OK for 0 and 2. none for 1 ERROR otherwise Command options: ATQ0 = Allows the modem to send result codes to the DTE. ATQ1 = Prohibits the modem from sending result codes to the DTE. ATQ2 = Modem returns result codes to the DTE when originating a call; does not return result codes when answering a call with the exception of OK and ERROR. ATSn? -- Reading S Registers. Reads the contents of the S register. All the S register may be read. Parameters: n= 0-95 Default: none Result codes: OK for all parameters. ATSn=x -- Writing to S Registers. Writes the value of x to the specified S register. All the register will return the OK response if x is a legal value, however, some registers will not actually write the value anywhere. These registers are S1, S13-S15, S17, S20-S24, and S27. Parameters: n= 0-95, x= 0-255 Default: none Result codes: OK for parameters n= 0-95. OK for no argument. ERROR otherwise. ATT -- Set Dial Tone as Default. Causes the modem to assume that all subsequent dial strings are tone dialed. The user may omit the "T" from the dial string. Parameters: none Default: none Result codes: OK If issued outside dial string. ATVn -- Result Code Form (Message Control). Selects whether the modem sends long form or short form result codes to the local DTE. All responses are ASCII values. Long-form (verbose) responses are preceded and terminated with both carriage return and line feed control characters. Short-form (numeric) responses are only terminated with a carriage return control character (See ATXn command). Parameters: 0,1 Default: 1 Result codes: 0 for 0 OK for 1 ERROR otherwise Command options: ATV0 = Allows short-form (numeric) result codes to be sent. ATV1 = Allows long-form (verbose) result codes to be sent. ATWn -- Negotiation Progress Reporting. An additional set of result codes can be enabled with the W command to report progress of the negotiation phase of error-correction mode. These codes report the carrier speed (300bps - 14,400bps) and the error-correction protocol. These messages can also be reported in either numeric or verbose form. For example, both 77 and PROTOCOL:LAP-M indicate that the error correction protocol is LAP-M (See ATXn command). If the error-correction link is negotiated and a connection is made, the appropriate CONNECT XXXX message is reported. When in error-correction mode, the CARRIER XXXX message may indicate one speed, while the CONNECT XXXX message reports another. Parameters: 0-2 Default: 0 Result codes: OK for parameters 0-2. ERROR otherwise Command options: ATW0 = Error-correction call progress not reported. ATW1 = Error-correction call progress reported. ATW2 = Error-correction call progress not reported. COMMECT XXXX message reports DCE speed. ATXn -- Extended Result Codes. Determines whether the modem responds to dial tone and busy signals, and how it displays result codes for CONNECT messages. When the modem ignores dial tone, it waits for a time delay given by register S6 (default=2 seconds) and then dials regardless of presence or absence of dial tone; this is called blind dialing. Parameters: 0-4 Default: 4 Result codes: OK for parameters 0-4. ERROR otherwise. Command options: ATX0 = Modem ignores dial tone and busy signal. CONNECT message when a connection is established by blind dialing. ATX1 = Modem ignores dial tone and busy signal. Sends CONNECT XXXX message reflecting bit rate when a connection is established by blind dialing. ATX2 = Modem ignores busy signal but waits for dial tone before dialing. If dial tone is not detected within 5 seconds, the NO DIAL TONE message is sent. Sends CONNECT XXXX message reflecting but rate when a connection is established. ATX3 = Modem ignores dial tone. Sends BUSY message if a busy signal is detected. Sends CONNECT XXXX message reflecting bit rate when a connection is established by blind dialing. ATX4 = If dial tone is not detected within 5 seconds, sends NO DIAL TONE message. If busy signal is detected, sends BUSY message. Sends CONNECT XXXX message reflecting bit rate when a connection is established. Result codes - Q, V, X, W, S95 Short form Long form 0 OK 1 CONNECT 2 RING 3 NO CARRIER 4 ERROR 5 CONNECT 1200 6 NO DIALTONE 7 BUSY 8 NO ANSWER 9 CONNECT 0600 10 CONNECT 2400 11 CONNECT 4800 12 CONNECT 9600 14 CONNECT 19200 28 CONNECT 38400 CONNECT 57600 40 CARRIER 300 46 CARRIER 1200 47 CARRIER 2400 49 CARRIER 7200 50 CARRIER 9600 51 CARRIER 12000 52 CARRIER 14400 66 COMPRESSION CLASS 5 67 COMPRESSION V.42 BIS 69 COMPRESSION NONE 70 PROTOCOL: NONE 77 PROTOCOL: LAPM 80 PROTOCOL: ALT ATYn -- Control Long Space Disconnect. Determines whether the modem disconnects when it receives a continuous break from a remote modem for a period equal to, or greater than, 1.6 seconds, and sends a break for 4 seconds before disconnecting due to an ON-to-OFF transition of DTR if an AT&D2 option is in effect, or upon receiving an ATH command. Parameters: 0,1 Default: 0 Result codes: OK for 0 and 1 ERROR otherwise Command options: ATY0 = Disable long space disconnect. ATY1 = Enable long space disconnect. ATZn -- Reset. Causes the modem to disconnect and performs a warm start. This command must be the last command on the command line. The reset actions are: -Clear serial port buffers -Set the baud rate and parity to match the local DTE when any AT command is issued. -Restore the active configuration with the user profile denoted by the parameter. Parameters: 0,1 Default: 0 Result codes: OK for 0 and 1 ERROR otherwise AT&Cn -- DCD Option. Controls the Received Line Signal Detected (RLSD) [Carrier Detect (DCD)] signal of the serial port. If synchronous mode is selected, this command is ignored and the modem functions as if the AT&C1 command has been entered. Parameters:n= 0,1 Default: 0 Result codes: OK for 0 and 1 ERROR otherwise Command options: AT&C0 = RLSD is ON regardless of the state ofhte data carrier from the remote modem. AT&C1 = RLSD follows the state of the data carrier from the remote modem. AT&Dn -- DTR Options. Determines actions taken by the modem in relation to the Data Terminal Ready (DTR) signal of the serial port. The effect of DTR loss depends upon the AT&D and AT&Q (AT&M) commands. Parameters: n= 0-3 Default: 0 Result codes: OK for 0 to 3 ERROR otherwise The action for the event that follows DTR loss is indicated in the following table &D0 &D1 &D2 &D3 &Q0 NONE 2 3 4 &Q1 1 2 3 4 &Q2 3 3 3 3 &Q3 3 3 3 3 &Q4 1 2 3 4 The DTR-going-off events corresponding to the action number in the above table are: 1) Modem disconnects and sends OK result code. 2) Modem goes into command mode if in data mode and sends the OK result code. 3) Modem disconnects, sends the OK result code, and disables auto answer while DTR is OFF. 4) Modem performs a warm start (for example, same as the ATZ command). This is the DTE/AT&D3 abort. 5) If AT&Q5, AT&Q8, or AT&Q9 is in effect, the action taken is the same as AT&Q0. AT&F -- Restore Factory Configuration. Loads the modem active configuration area with the factory default values. Parameters: none Default: none Result codes: OK AT&Gn -- Set Guard Tone. Normally controls the generation of guard tones. This command is not implemented, however, the command structure is provided for application compatibility. Parameters: n= 0-2 Default: o Result codes: OK for 0 to 2 ERROR otherwise AT&Jn -- Telephone Jack Selection. Determines how the auxiliary relay is controlled. Parameters: n= 0,1 Default: 0 Result codes: OK for 0 and 1 ERROR otherwise Command options: AT&J0 = Suitable for RJ-11, RJ-41S, or RJ-45S type phone jack. The auxiliary relay is never operated. AT&J1 = Sutiable for RJ-12 or RJ-13 type phone jack. The A lead is connected to A1 lead while modem is off-hook. If AT&J0 is selected, the auxiliary telco relay is opened. If AT&J1 is selected and the modem is off-hook, the auxiliary telco relay (A/A1) is closed (shorting A to A1). AT&Kn -- DTE/Modem Flow Control. Determine how the modem controls the flow of data between the local DTE and the modem. When the modem terminal buffer is nearly full, the modem will either send an XOFF or drop CTS to stop data flow. When the buffer is nearly empty, the modem will either send an XON or raise CTS to start the data flow. The modem also responds to XON/XOFF characters or RTS stimulus from the DTE by suspending or resuming transmission accordingly. The modem responds to DTE XON/XOFF characters and also passes the XON/XOFF characters to the remote modem as data if transparent flow control is selected. When in the direct mode (AT&Q0), flow control is not used and the modem ignores the setting of this command. Parameters: n= 0,3,4, or 5 Default: 3 Result codes: OK for 0 and 1 ERROR otherwise Command options: AT&K0 = Disables flow control AT&K3 = Enables RTS/CTS flow control AT&K4 = Enables XON/XOFF flow control AT&K5 = Enables transparent XON/XOFF flow control AT&Ln -- Line Type. Controls selection of leased line or dial-up line. Although the modem has only a single leased line operation. Parameters: n= 0,1 Default: 0 Result codes: OK for 0 and 1 ERROR otherwise Command options: AT&L0 = Dial-up line AT&L1 = Leased line AT&Mn -- Communication Mode. Same as AT&Q0 - AT&Q3. Parameters: n= 0-3 Default: &Qn Result codes: OK for 0-3 ERROR otherwise AT&Pn -- Dial Pulse Ratio. Selects the ratio of the off-hook (make) to on-hook (break) interval used when pulse dialing. Parameters: n= 0,1, or 2 Default: 0 for U.S.; 2 for Japan Result codes: OK for n= 0-2 in U.S. or for n= 1-2 in Japan ERROR otherwise Command options: AT&P0 = 39%/61% make/break ratio @ 10 pps. AT&P1 = 33%/67% make/break ratio @ 10 pps. AT&P2 = 33%/67% make/break ratio @ 20 pps. AT&Qn -- Communication Mode. The modem supports three basic communication modes: asynchronous, synchronous, and error correction. Synchronous and Direct modes are not available when the parallel host interface is selected. Parameters: n= 0-9 Default: 5 Result codes: OK for 0-9 ERROR otherwise Command options: AT&Q0 = Selects asynchronous operation in the Direct mode. In this mode, the DTE speed must match the telco line speed AT&Q1 = Selects synchronous mode 1 operation. Supports terminals that are able to communicate in both asynchronous and synchronous protocols. Uses the dial command to place a call in asynchronous mode then switches to synchronous mode once the connection has been made. The modem goes on-hook and switches back to the asynchronous mode when it detects an ON-to-OFF transition on DTR or a loss of carrier from the remote modem exceeding the time interval given by register S10 (default = 1.4 seconds). AT&Q2 = Selects synchronous mode 2 operation. Supports synchronous terminals with stored number dialing. The modem automatically dials a stored number when it detect an ON-to-OFF transition on DTR. An asynchronous terminal is still needed to save or change the phone number stored in the NVRAM; the number is saved using the "AT&Z0=x" command. The modem dials the number stored in the first entry. The modem goes on-hook and switches back to the asynchronous mode when an ON-to-OFF transition on DTR is detected or a loss of carrier occurs from the remote modem excedding the time interval given by register S10 (default = 1.4 seconds) AT&Q3 = Selects synchronous mode 3 operation. This mode allows DTR to act as a Talk/Data switch. The operator manually initiatesa call with DTR OFF, implying the modem is in TALK mode. To complete the call, the operator switches the modem to DATA mode by turning DTR ON after the last number is dialed. The modem goes on-hook and switches to the asynchronous mode whe an ON-to-OFF transition on DTR is detected or a loss of carrier occurs from the remote modem exceeding the time interval given by register S10 (default = 1.4 seconds). AT&Q4 = This command causes the modem to issue OK result code but has no effect on operation. AT&Q5 = Selects error correction mode. Modem negotiates an error-correction link. The modem can be configured to either disconnect or fallback to a normal asynchronous connection if the link cannot be negotiated. AT&Q5 and S36=0: same as AT\N2 (no fallback) AT&Q5 and S36=1: same as AT\N3 (fallback) AT&Q6 = Selects asynchronous operation in Normal mode (Speed Buffering). In this mode, the DTE speed can differ from the telco line speed. AT&Q7 = This command causes the modem to issue OK result code but has no effect on operation. AT&Q8 = This command forces the modem to behave as if S48=128, fallback to MNP for example. If bit 1 of S36=1, then the modem acts as if S36=1, then the modem acts as if S36=7. Otherwise, it acts as if S36=5. AT&Q9 = This command behaves like AT&Q5 with S48=7 and S46=138. The modem will attempt V.42bis, fallback to V.42 (LAP-M), then fallback to normal mode. AT&Rn -- RTS/CTS Option. Controls state of the CTS signal in he synchronous mode. CTS is always on in the asynchronous mode unless AT&K3 has been selected. Parameters: n= 0,1 Default: 0 Result codes: OK for 0 and 1 ERROR otherwise Command options: AT&R0 = CTS tracks RTS. CTS is turned ON in response to an OFF-to-ON transition of RTS from the local DTE after a delay period specified by register S26 in increments of 10 milliseconds (default = 0). AT&R1 = The modem ignores RTS; CTS is held ON unless AT&K3 has been selected. AT&Sn -- DSR Option. Determines whether DSR operates in accordance with the EIA-232-D specification or remains ON. Parameters: n= 0,1 Default: 0 Result codes: OK for 0 and 1 ERROR otherwise Command options: AT&S0 = DSR is always ON. AT&S1 = DSR operates in accordance with the EIA-232-D specification. AT&Tn -- Test and Diagnostic. Selects the test command. Test commands must be initiated in the command mode with asynchronous operation in the Direct mode selected (AT&Q0) at a speed of 1200 bps or faster. A telco line connection must be established prior to initiating digital loopback tests. If these conditions are not met, the modem issues the ERROR result code and pulses the TML output to indicate an error. If local analog loopback is initiated while the modem is connected, the modem disconnects before performing the test. During a test, the modem sets the TML output low to turn the TEST indicator on. If an error is detected, or the line was not connected for remote digital loopback test, the TML output is pulsed to blink the TEST indicator. An initiated test is active for a period of time specified by register S18 (test timer) before returning to the command mode. If S18 is zero, the test aborts when the user issues the AT&T0 command. Parameters: 0,1 or 3-8 Default: 4 Command options: AT&T0 = End test in progress. The escape sequence must be issued to return the modem to the command mode prior to sending this command. Subsequent issuing of the ATO command while in the command mode will cause the local and remote modems to return to normal data mode operation if the interrupted test was digital loopback. AT&T1 = Initiates local analog loopback. This test verifies the working condition of the path between the local DTE and the local modem. The characters received from the DTE are looped back to the DTE by the modem. AT&T3 = Initiates remote digital loopback locally. The characters received from the remote modem are looped back to the remote modem by the local modem. This test verifies the working condition of the path from the remote modem, through a local modem, and back to the remote modem. AT&T4 = Allows the modem to respond to a request from a remote digital loopback test. AT&T5 = Prohibits the modem from granting a request from a remote modem for a remote digital loopback test. AT&T6 = Initiates remote digital loopback. The characters received from the local DTE are transmitted to the remote modem and looped back from the remote modem to the local modem and DTE. This test verfies the working condition of he path between the local DTE and the remote modem. AT&T7 = Initiates remote digital loopback with self test. This test works similarly to AT&T6 except that the modem sends an alternating zeros and ones (0101) test pattern to the remote modem and continuously examines the validity of the returned data. The modem increments an internal error counter each time an error is detected. At the end of the test, the modem returns a 3-digit error count to the DTE. AT&T8 = Initiates local analog loopback with self test. This test works similarly to AT&T7 except that the test pattern is checked in the local analog loopback mode (as in AT&T1). This allows a thorough testing of the local modem transmit and receive functions without an actual telco line connection. AT&V -- View Current Configuration and User Profiles. Displays the active configuration and user profiles. Parameters: none Default: none Result codes: OK AT&Wn -- Store User Profile. Saves the current configuration into NVRAM as one of two user profiles. The current configuration is comprised of a list of storable parameters illustrated in the AT&V command. These settings are restored to the active configuration upon receiving an ATZn command or at power up (see AT&Y command). The user profile saved is denoted by the parameter value. Parameters: n= 0,1 Default: none Result codes: OK for 0 and 1 ERROR otherwise Command options: AT&W0 = Save as user profile 0. AT&W1 = Save as user profile 1. AT&Xn -- Clock Source Selection. Selects the source of the synchronous transmit clock for hte modem during synchronous operation. In asynchronous mode, the transnit and receive clocks are turned OFF. In synchronous mode, the clocks are turned ON with the frequency of 2400Hz or 1200Hz corresponding to the speed that is selected for modem operation. Parameters: n= 0-2 Default: 0 Result codes: OK for 0 and 2 ERROR otherwise Command options: AT&X0 = Internal timing. The modem generates tha transmit clock signal and applies it to the EIATXCLK output at the serial interface. AT&X1 = External timing. The local DTE sources the transmit clock signal on the SPEXTCLK input of the serial interface. The modem applies this clock to the EIATXCLK output at the serial interface. AT&X2 = Slave receive timing. The modem derives the transmit clock signal from the incoming carrier and applies it to the EIATXCLK output at the serial interface. AT&Yn -- Designate Default User Profile. Designates which of two users profiles will be loaded into active configuration at power up. The user profile is denoted by the parameter value. Parameters: 0,1 Default: 0 Result codes: OK for 0 and 1 ERROR otherwise Command options: AT&Y0 = Selects user profile 0. AT&Y1 = Selects user profile 1. AT&Zn=x -- Store Phone Number. Stores a 36-digit dial string (x) in the specified entry (n) for later dialing. (See ATDS=n command). Parameters: n= 0-3, x= dial string Default: none Result codes: OK for all parameters ERROR if storage number (n) is outside allowable range, the dial string (x) is longer than 36-digits, or if the total number of stored digits in all entries exceeds 114. AT\An -- Maximum MNP Block Size. Sets maximum block size for MNP stream link connections. Use this command to transmit smaller blocks of data in a reliable link connection. Parameters: n= 0-3 (if in greater than 3, 3 is used) Default: 2 Result codes: OK Command options: AT\A0 = Sets maximum block size to 64 characters. AT\A1 = Sets maximum block size to 128 characters. AT\A2 = Sets maximum block size to 192 characters. AT\A3 = Sets maximum block size to 256 characters. AT\Bn -- Transmit Break. When this command is entered during a non-MNP commection, the modem sends a break signal to the remote modem. The length of the break is 100 times the n parameters value in milliseconds. If this command is entered in MNP mode, the modem sends a Link Attention PDU to the rewmote modem. Parameters: n= 1-9 (if n=0, the default value 3 is used; if n is greater than 9, 9 is used) Default: 3 Result codes: OK if connected. NO CARRIER if not connected. AT\En -- Optimize Echo Cancellation. The AT\E command is a one-shot command that can be used to optimize the local echo. When the AT\E1 command is issued before a call is originated or answered, the modem will set NET1 and NET2 so that the local echo is minimized (attempting to match the local network for example). After an optimization (AT\E1), NET1 and NET2 will remain in their optimized state until another connection is attempted following an AT\E command, or a reset. The state of NET1 and NET2 is not stored in the NVRAM. NET1 and NET2 default to 0 and 1, respectively, at power up/reset. AT\Gn -- Modem to Modem Flow Control. Enables or disables modem to modem flow control during a Normal mode connection. Since the reliable link (error correction) has it's own method of flow control, the AT\Gn command is ignored when error correction is selected (AT&Q5, QT&Q8, or AT&Q9). However, the DTE to modem flow control remains active during a reliable link. Parameters: n= 0, 1 (if n is greater than 1, 1 is used) Default: 0 Result codes: OK Command options: AT\G0 = Disables flow control (XON/XOFF). AT\G1 = Enables flow control (XON/XOFF). AT\Kn -- Break Control. Determines the modems response when a BREAK is received from the DTE or the remote modem. During MNP mode, the remote modem's BREAK control setting determines the local modem response to handle the BREAK. Parameters: n= 0-5 (if n is greater than 5, 5 is used) Default: 5 Result codes: OK Command options: When a BREAK is received from the DTE during Normal or MNP mode, the modem responds as follows: AT\K0, 2, 4 = Modem enters the command mode (waiting for AT) without sending a BREAK to the remote modem. AT\K1 = Modem clears the terminal and modem buffers but send a BREAK to the remote modem. AT\K3 = MOdem does not clear the buffers but sends a BREAK to the remote modem. AT\K5 = Modem semds a BREAK to the remote modem in sequence with any transmitted data. When a BREAK is received from the DTE during Direct mode, the modem takes the following action: AT\K0, 2, 4 = Modem sends a BREAK to remote modem and enters command mode (waiting for AT). AT\K1, 3, 5 = Modem sends a BREAK to remote modem. ---------------------------------------------------------------------- Note: In LAPM, breaks are "timed", meaning the modem attempts to preserve the duration of the break when transmitting it to the remote modem. In MNP4, breaks are not "timed", as MNP4 has no facility for maintaining the duration of a signal; a long break is the same as a short break. ---------------------------------------------------------------------- AT\Ln -- NMP Block Transfer Control. Determines whether the modem will use Block or Stream mode for MNP link. Parameters; n=0, 1 (if n is greater than 1, 1 is used) Default=0 Result codes: OK Command options: AT\Lo = Uses Stream mode for MNP link connections. AT\L1 = Uses Block mode for MNP link connections. AT\Nn -- Operation Mode Control. Selects the operating mode the modem uses while connected (see AT&Qn command). Parameters: n= 0-3 (if N is greater than 3, 3 is used) Default = 3 Result codes: OK Command options: AT\N0 = Selects normal (speed buffering) mode. This option takes effect at physical connection time. AT\N1 = Selects Direct (pass through) mode. This option takes effect at physical connection time. If the parallel interface is selected, the AT\N1 is interpreted as AT\N0, since Direct mode is not available with the parallel interface. AT\N2 = Selects reliable link mode. This defines the modem-to-modem connection to require error correction. If an attemp to establish the reliable link fails, the modem disconnects. This command takes effect at physical connection time only. To establish MNP after a physical connection, use the AT\O, AT\U, or AT\Y command. AT\N3 = Selects auto-reliable link mode. The modem will attempt an error-correction connection but will fallback to Normal mode if unable to establish an MNP link. This command takes effect at connect time only. To establish MNP after a physical connection, use the AT\O, AT\U, or AT\Y command. AT\O -- Originate Reliable Link Control. Forces the modem to originate an MNP connection regardless of whether the modem is in originate or answer mode. The modem will send up to two link requests. If the remote modem does not respond after the second request, the modem returns to its previous state. This command can only be executed if a physical connection exists, and will return the NO CARRIER message if there is no connection, or an appropriate connect message if a reliable link connection already exists. This command must be the last command on a command line. Parameters: none Default: none AT\Tn -- Inactivity Timer Control. Determines the length in 1-minute intervals that the modem will wait before disconnecting when no data is sent or received. In MNP mode, any data transmitted or received by the modem will reset the timer. In non-MNP mode, any data transmitted will reset the timer. The inactivity timer is inoperative in synchronous mode and in direct mode. Parameters: n=0-42 (if n is greater than 42, 42 is used) Default = 0 Result codes : OK AT\U -- Accept Reliable Mode Control. Causes the modem to wait up to 12 seconds for a link request from the remote modem to establish an MNP link, regardless of whether the modem is in originate or answer mode. If the Link Request is not received within this time period, the modem returns to its previous state. This command can only be executed if a physical connection exists, and will return the NO CARRIER message if there is no connection, or an appropriate connect message if a reliable link connection already exists. This command must be the last command on a command line. Parameters: None Default : None AT\Y -- Switch to Reliable Mode. Causes the modem to try to establish a reliable link. Depending on whether the modem is in originate or answer mode, the modem either accepts a link request from the remote modem or sends a link request, respectively. If the MNP connection attempt fails, the modem returns to its previous state. This command can only be executed if a physical connection exists, and will return the NO CARRIER message if there is no connection, or an appropriate connect message if a reliable link connection already exists. This command must be the last command on a command line. Parameters: None Default : None AT\Z -- Switch to Normal Mode. Causes the modem to switch to normal mode after a reliable link is established. Switching to normal mode erases any data that may be in the terminal and modem buffers. This command can only be executed if a physical connection exists, and will return the NO CARRIER message if there is no connection, or an appropriate connect message if a reliable link connection already exists. This command must be the last command on a command line. Parameters: None Default : None AT%Cn -- Compression Control. Determines whether or not the modem will use data compression. Parameters : 0,1 (if n is greater than 1, 1 is used) Default : 1 Result Codes :OK Command Options: AT%C0=Disables data compression AT%C1=Enables data compression AT%Dn -- Set dictionary size (V.42bis). Sets the V.42 bis dictionary size. Parameters: 0-3 Default : 2 Result Codes : OK Command options: AT%D0 = 512 AT%D1 = 1024 AT%D2 = 2048 AT%D3 = 4096 (one-way compression only *) *For two-way compression (AT%M3), the dictionary size is set for 2048 if AT%D3 is issued. AT%En -- Enable/Disable Auto-Retrain. Determines whether or not the modem automatically monitors the line quality and requests a retrain when necessary during a 9600, 4800, or 2400 bps connection. Parameters : n=0,1 (if n is greater than 1, 1 is used) Default : 0 Result Codes : OK Command options : AT%E0 = disables auto-retrain AT%E1 = enables auto-retrain AT%L -- Report Received Signal Level. Returns a value identifying the received signal level. The possible values are: 009=Received level of -9 dBm 010=Received level of -10 dBm ...... 043=Received level of -43 dBm If the received level is greater than -9 dBm, 009 will be reported. If the received level is less than -43 dBm, 043 will be reported. Parameters : None Default : None Result Codes : OK AT%Mn -- Set One/Two-Way Compression Mode (v.42bis). Selects the one/two-way compression mode when using v.42bis compression. Parameters : 0-3 Default : 3 Command Options : AT%M0 = Compression Disabled AT%M1 = Transmit compression only AT%M2 = Receive compression only AT%M3 = Two-way compression AT%P -- Clear V.42bis Encoder Dictionary. Resets the local modem v.42bis. encoder dictionary and sends a command code to the remote modem to reset the remote v.42bis dictionary. Parameters : none Default : none Result Codes : OK - if encoder dictionary is in use ERROR - if encoder dictionary is not in use. AT%Q -- Report Line Signal Quality. Returns the high-order byte of the calculated Eye Quality Moniter (EQM) value. The high-order byte can range from 0 to 255. However, when the value is 8 or greater, the modem will automatically retrain if enabled by the AT%E1 command. The value for a normal connection ranges from about 0 to 2 and approaches 8 for a progressively poorer connection. Parameters : none Default : none Result Codes : OK AT%Sn -- Set Maximum String Length (V.42bis). Sets the maximum number of characters that can be compressed onto one word. Parameters : 6-250 Default : 32 characters ------------------------------------------------------------------------ S Registers The registers are summarized in the following table along with their default values. Registers denoted with an (*) may be stored in one of the two user profiles by entering the AT&Wn command. One of these profiles can be loaded at any time by using the ATZn command. ------------------------------------------------------------------------ Register Title Default -------- ------------------------------ ------- S0 Number of rings till Auto-Answer 0 * S1 Ring Counter 0 S2 Escape Character 43 S3 Carriage Return character 13 S4 Line Feed character 10 S5 Back Space character 8 S6 Wait for Blind Dialing 2 * S7 Wait for Carrier after dial 50 * S8 Pause time for delay dial 2 * S9 Carrier detect response time 6 * S10 Lost carrier to hangup delay 14 * S11 DTMF Tone duration 95 * S12 Escape code guard time 50 * S13 Reserved none S14 Bit mapped options none * S15 Reserved none S16 Bit mapped test options none S17 Reserved none S18 Test timer 0 * S19 Reserved 0 S20 Reserved none S21 Bit mapped options none * S22 Bit mapped options none * S23 Bit mapped options none * S24 Reserved none S25 Delay to DTR 5 * S26 RTS to CTS Delay interval 1 * S27 Bit mapped options none * S28-S29 Reserved none S30 Inactivity timer 0 * S31-S35 Reserved none S36 Negotiation Failure treatment 7 * S37 Desired Telco line speed 0 * S38 Delay before forced disconnect 20 * S39 Reserved none * S40 Bit mapped options (MNP) 77 S41 Bit mapped options (MNP) 1 S44 Unused 3 * S46 Protocol Selection none * S48 V.42 Negotiation action 7 * S49 Speed Buffer lower limit 8 ** S50 Speed Buffer upper limit 255 ** S82 Break handling 128 * S86 Connection Failure cause code none * S91 Programmable Transmit level 0 (US) * 15 (Japan) S95 Extended Result codes 0 * * Register value may be stored in on of two user profiles with the AT&Wn command. ** Not used. ------------------------------------------------------------------------ Factory Defaults: The factory defaults are stored in ROM and are loaded into the active configuration at power up or by the ATZn command. In addition, the designated default profile is subsequently loaded, and may change some of the factory default values. The designated default profile can be changed by entering the AT&Yn command where n is one of the two possible user profiles. All of the factory defaults values may be loaded at any time by entering the AT&F command. The S registers are described in detail following... ----------------------------------------------------------------------- S0 Number of Rings till Auto-Answer. Establishes the number of rings required before them modem answers the incoming calls. Setting this register to zero disables auto-answer mode. Range: 0-255 rings Default: 0 S1 Ring Counter. Number of the rings which the modem detects before it answers a call. If no ring occurs over an eight second interval, this register is cleared. Range: 0-255 rings Default: 0 S2 Escape character. S2 holds the decimal value of the ASCII character used for the escape character. The default value corresponds to an ASCII '+'. A value over 127 disables the escape process (for example, no escape character will be recognized). Range: 0-255, ASCII decimal Default : 43 S3 Carriage Return Character. Sets the commanf line and result code terminator character. Pertains to asynchronous only. Range: 0-127 ASCII decimal Default: 13 (Carriage Return) S4 Line Feed Character. Sets the character recognized as a line feed. Pertains to asynchronous operation only. The line feed control character is output after the Carriage Return control character if verbose result codes are used. Range: 0-127, ASCII decimal Default: 10 (line feed) S5 Backspace Character. Sets the character recognized as a backspace. Pertains to asynchronous operation only. The modem will not recognize the Backspace character if it is set to a value that is greater than 32 ASCII. This character can be used to edit a command line. When the echo command is enabled, the modem echoes back to the local DTE the Backspace character, an ASCII space character and a second Backspace character, this means a total of three characters are transmitted each time the modem processes the Backspace character. Range: 0-32, ASCII decimal Default: 8 (Backspace) S6 Wait Time for Blind Dialing. Sets the length of time to pause after the modem goes off-hook and before the modem dials the first digit of the telephone number. The modem always pauses for a minimum of two seconds even if the S6 register is set to a value less than 2 seconds. The "Wait for Dial Tone" call progress feature (W in the dial string) will override the value in register S6. If option ATX2 or ATX4 is in effect, this register is ignored. Range: 2-255 seconds Default: 2 S7 Wait for Carrier after Dial. Defines two delay times: 1) During call establishment, this register establishes the time that the local modemwaits for carrier from the remote modem before hanging up. 2) Sets the length of time that the modem waits when the "Wait for Dial Tone" call progress feature (W in the dial string) is in effect. Range: 1-255 seconds Default: 50 S8 Pause Time for Dial Delay. Sets the length of time to pause when the modem encounters the "Pause During Dial" call progress feature, for example the comma (,). Range: 0-255 seconds Default: 2 S9 Carrier Detect Response Time. Determines how long a carrier signal must be present before the modem recognizes it has a carrier and turns on RLSD. As this time is increased, there is less chance to detect a false carrioe due to noise from the telco line. Range: 1-255 tenths of a second Default: 6 (.6 second) S10 Lost Carrier to Hang up Delay. Sets the length of time the modem waits before hanging up after a loss of carrier. This allows for a temporary carrier loss without causing the local modem to disconnect. When register S10 is set to 255, the modem functions as if a carrier is always present (except in error correcting modes, in which case the modem will disconnect). The actual interval the modem waits before disconnecting is the value in register S10 minus the value in register S9. Therefore, the value in S10 must be greater than the S9 value or else the modem disconnects before it recognizes the carrier. Range: 1-255 tenths of a second Default: 14 (1.4 seconds) S11 DTMF Tone duration. Sets the duration of the tones in Dual Tone Multifrequency (DTMF) dialing. This value has no effect on pulse dialing. Range: 50-255 milliseconds Default: 95 milliseconds S12 Escape Code Guard Tone. Sets the time delay required immediately before and after entering the escape code. The time interval between the sending of the first and second, or the second and third escape code character must be less than the guard time. Range: 0-255 fiftieths of a second Default: 50 (1 second) S13 Reserved S14 Bit mapped options. Indicates the status of command options. Bit 0 = AFT 0 - disabled 1 - enabled Bit 1 = ATE 0 - disabled 1 - enabled Bit 2 = ATQ 0 - disabled 1 - enabled Bit 3 = ATV 0 - numeric 1 - verbose Bit 4 = reserved Bit 5 = ATP or ATT 0 - ATT 1 - ATP Bit 6 = Part of ATQ 0 - ATQ0,1 1 - ATQ2 Bit 7 = Originate/Answer 0 - Answer 1 - Originate S15 Reserved S16 Bit mapped test options. Indicates the test in progress. The TSTIND output is turned ON when S16 is non-zero to indicate that a test is in progress. The AT&T0 terminates any test and set S16 to zero. **NOTE - if the Modem Ready LED function is selected in the CONFIGURATION byte, the Modem Ready indication (TSTIND) will be turned off during test modes. Default: 0 Bit 0 = Local analog loopback (AT&T1) 0 - disabled 1 - enabled Bit 1 = Not used Bit 2 = Local digital loopback (AT&T3) 0 - disabled 1 - enabled Bit 3 = Remote digital loopback status (AT&T6) 0 - loopback off 1 - loopback in progress Bit 4 = Remote digital loopback (AT&T6) 0 - disabled 1 - enabled Bit 5 = Remote digital loopback w/ self test (AT&T7) 0 - disabled 1 - enabled Bit 6 = Local analog loopback with self test (AT&T8) 0 - disabled 1 - enabled Bit 7 = Not used S17 Reserved S18 Test timer. Sets the length of time the modem conducts a test before returning to the command mode. If this register is zero, the test will not automatically terminate; the test must be terminated from the command mode by issuing an AT&T0 or ATH command. Range: 0-255 seconds Default: 0 S19 Reserved S20 Reserved S21 Bit Mapped Options. Indicates the status of command options. Bit 0 0 - AT&J0 1 - AT&J1 Bit 1 0 - AT&Y0 1 - AT&Y1 Bit 2 0 - AT&R0 1 - AT&R1 Bit 3,4 0 - AT&D0 1 - AT&D1 2 - AT&D2 3 - AT&D3 Bit 5 0 - AT&C0 1 - AT&C1 Bit 6 0 - AT&S0 1 - AT&S1 Bit 7 0 - ATY0 1 - ATY1 S22 Bit Mapped options. Indicates the status of command options. Bit 0,1 0 - ATL0 1 - ATL1 2 - ATL2 3 - ATL3 Bit 2,3 0 - ATM0 1 - ATM1 2 - ATM2 3 - ATM3 Bit 4,5,6 0 - ATX0 1 - ATX1 2 - ATX2 3 - ATX3 4 - ATX4 5 - Invalid code 6 - Invalid code 7 - invlaid code Bit 7 0 - AT&P0 1 - AT&P1 S23 Bit Mapped Options. Indicates the status of command options. Bit 0 0 - AT&T5 1 - AT&T4 Bit 1,2,3 = Local DTE Rate 0 - 0-300 bps 1 - 600 bps 2 - 1200 bps 3 - 2400 bps 4 - 4800 bps 5 - 9600 bps 6 - 19200 bps 7 - 38400 bps Bit 4,5 = Parity Option 0 - even 1 - not used 2 - odd 3 - none Bit 6,7 0 - AT&G0 1 - AT&G1 3 - AT&G2 S24 Reserved S25 Delay to DTR. Register S25 serves two purposes. When the modem is operating in synchronous mode 1, the value assigned to S25 specifies the length of time the modem waits after a connection has been made before examining DTR. This allows the modem to ignore an ON-to-OFF transition of DTR giving the user sufficient time to disconnect the modem from the asynchronous terminal and attach it to the synchronous terminal, without forcing the modem back to the asynchronous command mode. During this time, the value for S25 is read in seconds. In all other modes, and after call establishment in synchronous modes 1 and 4, the value is read in 1/100 seconds. In any mode. a change in DTR (ON or OFF) that persists for a period shorter than the value held in S25 is ignored by the modemwhile it is in data mode. Range: 0-255 (.01 second if mode 1 or 4 when in data mode, 1 second otherwise) Default: 5 S26 RTS to CTS Delay Interval. Pertains to synchronous operation only. When CTS tracks RTS (AT&R0) and the modem detects an ON to OFF transition on RTS, this register sets the time delay before the modem turns CTS ON. Range: 0-255 hundredhs of a second Default: 1 S27 Bit Mapped Option. Indicates the status of command options. Bit 0,1,3 0 - AT&Q0 1 - AT&Q1 2 - AT&Q2 3 - AT&Q3 4 - AT&Q4 5 - AT&Q5 6 - AT&Q6 7 - AT&Q7 Bit 2 0 - AT&L0 1 - AT&L1 Bit 4,5 0 - AT&X0 1 - AT&X1 2 - AT&X2 Bit 6 0 - ATB0 1 - ATB1 Bit 7 Reserved S28-S29 Reserved S30 Inactivity Timer. Determines the length of time, in tenths of a second intervals, that the modem will wait before disconnecting when no data is sent or received. In MNP or v.42 mode, any data transmitted or received will reset the timer. In other modes, any data transmitted will reset the timer. The inactivity timer is inoperative in synchronous mode. Range: 0-255 Default: 0 (disabled) S31-S35 Reserved S36 Negotiation Failure Treatment. This register is read when the S48 register contains the value 128 or if an attempted error correction link fails. These fallback options are initiated immediately upon connection if S48=128. Range: 0-7 If an invalid number is entered, the number is accepted into the register, but S36 will act as if the default value is entered. Default: 5 The S36 actions are: S36=0 - Modem disconnects S36=1 - Modem stays online and a Direct mode connection is established. S36=2 - Reserved S36=3 - Modem stays online and a Normal mode connection is established S36=4 - An MNP connection is attempted and if it fails, the modem disconnects. S36=5 - An MNP connection is attempted and if it fails, a Direct Mode connection is established S36=6 - Reserved S36=7 - An MNP connection is attempted, and if it fails, Normal mode connection is established. S37 Desired Telco Line Speed Range: 0-7 If an invalid number is entered, the number is accepted into the register, but S37 will act as if the default value is entered. Default: 0 S37=0 Attempt to connect at speed of last AT command issued. For DTE speeds greater than 9600bps, the modem will attempt to connect at 9600bps. S37=1-3 Attempt to connect at 300bps. S37=4 Reserved S37=5 Attempt to connect at 1200bps S37=6 Attempt to connect at 2400bps. S37=7 Reserved S37=8 Attempt to connect at 4800bps S37=9 Attempt to connect at 9600bps S37=10 Attempt to connect at 12000bps S37=11 Attempt to connect at 14400bps S37=12 Attempt to connect at 7200bps S38 Delay Before Forced Disconnect (Error correction mode only) This register specifies the delay between the modem's receipt of the ATH command to disconnect (or ON-to-OFF transition of DTR if modem is programmed to follow the signal) and the disconnect operation. For an error-correction connection, this register can be used to ensure that data in the modem buffer is sent before the modem disconnects. IF S38 is set between 0 and 254, the modem will wait that number of seconds for the remote modem to acknowledge all data in the modem buffer before disconnecting. If time expires before all data is sent, the NO CARRIER result code will be issued to indicate that data has been lost. If all data is transmitted prior to time-out, the response to the ATH0 command will be OK. If S38 is set to 255, the modem does not time-out, and continues to attempt to deliver data in the buffer until the connection is lost, or the data is delivered. Range: 0-255 seconds Default: 20 S39 Reserved S40 Bit Mapped Options(MNP).Indicates the status of command options. Range: None Default: 0111 0111 Bit 0,1 =AT\N3 Bit 2,3,4=AT\K5 Bit 5,6 =AT\A3 Bit 7 =AT\G0 S41 Bit Mapped Options(MNP).Indicates the status of command options. Range: None Default: 0000 0001 Bit 0 =AT%C1 Bit 1 =AT%E0 Bit 2 =AT\L0 Bit 3,4,5,6,7 = Not used S46 Protocol Selection. Controls selection of compression. The following actions are executed for the given values: S46=136 - Execute error correction protocol with no compression S46=138 - Execute error correction protocol with compression In addition to v.42bis, the modem also implements MNP 5 data compression. v.42bis is used only with LAPM, and MNP 5 only with MNP 4. S48 V.42 Negotiation Action. The v.42 negotiation process determines the capabilities of the remote modem. However, when the capabilities of the remote modem are known and negotiation is unnecessary, this process can be bypassed if desired. Range: 0,7, or 128 If an invalid number is entered, it is accepted into the S register, but S48 will act as if 128 is entered. Default: 7 S48=0 - Disable negotiation; bypass the detection and negotiation phases; and proceed with LAPM S48=7 - Enable negotiation S48=128 -Disable negotiation; bypass the detection and negotiation phases; and proceed at once with the fallback action specified in S36. Can be used to force MNP S82 Break Handling Option. Break signals provide a way for the user to get the attention of the remote modem. The break type depends on the specific application. LAPM specifies three methods of break signal handling; in sequence, expedited, and destructive. Range: 3,7, or 128 If an invalid number is entered, it is accepted into the S register, but S82 will act as if the default value is entered. Default: 128 S82=3 Expedited: Modem sends a break immediately; data integrity is maintained both ahead of and after the break. S82=7 Destructive: Modem sends a break immediately; data being processed by each modem at the time of the break is destroyed. S82=128 In sequence: Modem sends a break in sequence with any transmitted data; data integrity is maintained both ahead of and after the break. (factory default) S86 Connection Failure Cause Code. When the modem issues a NO CARRIER result code, a value is written to this S register to help determine the reason for the failed connection. S86 records the first event that contributes to a NO CARRIER message. The cause codes are: S86=0 Normal disconnect, no error occurred. S86=4 Loss of carrier S86=5 V.42 negotiation failed to detect an error-correcting modem at the other end S86=9 The modems could not find a common protocol S86=12 Normal disconnect initiated by the remote modem S86=13 Remote modem does not respond after 10 re-transmissions of the same message S86=14 Protocol violation S91 Programmable Transmit Levels. The transmit level is adjustable in S91 from -0dBm (US default value) to -15dBm (Japanese default value) in 1dB increments for data transmission in both synchronous and asynchronous operation. This S register takes effect when the Japanese parameters are enabled or a leased line is selected. S91=0 0 dBm (US default) S91=1 -1dBm S92=2 -2dBm ... S92=15 -15dBm (Japanese default) The transmit level may not be changed once a connection exists. S95 Extended Result Codes. The bits in this register can be set to override some of the ATWn command options. A bit set to a 1 in this register will enable the corresponding result code regardless of the ATWn setting. Bit 0 - CONNECT result code indicates DCE speed instead of DTE speed Bit 1 - Append /ARQ to verbose CONNECT XXXX result code if protocol is not NONE Bit 2 - Enable CARRIER XXXX result code Bit 3 - Enable PROTOCOL XXXX result code Bit 4 - Reserved Bit 5 - Enable COMPRESSION result code Bit 6 - Reserved Bit 7 - Reserved ---------------------------------------------------------------------------