July 25, 1993 The complexity of modems today is such that great care must be taken in setting up the 'initialization string'. This string is what connects the modem to the outside world, and how it will react. My intention is to take some of the frustration out of setting up a modem for optimal use. As many modems come merely with a single sheet on how to install it in your computer, this text will aid you in getting the most out of your communications package. Jim Dickson Mississauga, Ontario Internet RN1020@ROSE.COM *************************************************************************** MODEM COMMANDS Command Function A manually answer incoming call A/ repeat last command executed. Do not precede A/ with AT or follow with ENTER. AT appear at the beginning of every command line B_ B0 = CCITT V.22/V.22bis compatibility B1 = Bell 103/212A compatibility D_ 0 through 9 # and * P (pulse dialing) R (include at end of Dial command line to call originate-only modem). T (touch-tone dialing) W (wait for second dial tone) @ (wait for one or more rings, followed by 5 seconds of silence. , (pause) ! (flash) ; (return to Command Mode after dialing) DS=n dials 1 of 4 telephone numbers (n) stored in the modem's nonvolatile memory E_ E0 = commands are not echoed E1 = commands are echoed +++ switch from Data Mode to Command Mode; pause 1 second before typing; do not follow with carriage return (se Registers S2 and S12. H_ H0 = modem is on-hook (hung up) H1 = modem is off-hook, line and auxiliary relay I_ I0 = display product identification code I1 = factory test I2 = internal memory test L_ L1 = low speaker volume L2 = medium speaker volume L3 = loud speaker volume M_ M0 = internal speaker off M1 = internal speaker off until carrier detected M2 = internal speaker always on M3 = speaker on until carrier detected and off while dialing O_ O0 = return to data mode O1 = modem does not send responses Sr? read value in register r (r = 0-27) Sr=n set register r to value n (r = 0-27; n = 0-255) V_ V0 = single digit response V1 = word responses X_ X0 = Hayes Smartmodem 300 compatibility X1 = include CONNECT 1200 and CONNECT 2400 responses X2 = include dial tone detection responses X3 = include busy signal detection responses X4 = include both dial tone and busy signal detection responses Y_ Y0 = modem does not send or respond to break signals Y1 = modem sends break signal for 4 seconds before discontinuing Z_ Z0 = retrieves active configuration profile from stored configuration profile 0 and performs 2 sec. modem self test Z1 = retrieves active modem configuration profile from stores configuration profile 1 &C_ &C0 = keep carrier detect signal always ON &C1 = turn on carrier detect signal when remote carrier signal is present &D_ &D0 = modem ignores the Data Terminal Ready signal &D1 = modem returns to command mode and asynchronous operation following an ON to OFF DTR transition &D2 = modem hangs up, returns to the command mode, and prepares for asynchronous operation following and ON to OFF DTR transition &D3 = modem resets following an ON to OFF DTR transition &F restores the modem to the default operating characteristics &G_ &G0 = guard tone disabled &G1 = 550 Hz guard tone &G2 = 1800 Hz guard tone &J_ &J0 = modem will use an RJ11, RJ41S, or RJ45S telephone jack &J1 = modem will use an RJ12 or RJ13 telephone jack &L_ &L0 = modem is set up for dialup operation &L1 = modem is set up for leased-line operation &M_ &M0 = modem is configured for asynchronous operation &M1 = modem enters synchronous mode after dialing asynchronously &M2 = synchronous terminal support only &M3 = manually originating a synchronous call &P_ &P0 = United States setting for off-hook(make) to on hook(break) ratio &P1 = UK and Hong Kong setting for off-hook to on-hook ratio &R_ &R0 = modem turns on its Clear To Send signal when it detects the Request To Send signal from the attached computer or terminal &R1 = modem ignores the Request To Send signal and turns on its Clear To Send when ready to receive data synchronously &S_ &S0 = DSR remains on at all times &S1 = DSR operates according to RS-232C specifications &T_ &T0 = ends test in progress &T1 = performs local analog loopback test &T3 = performs local digital loopback test &T4 = modem achnowledges remote digital loopback test performed by a remote modem &T5 = modem ignores a remote modem's request for a remote digital loopback test &T6 = perform a remote digital loopback test &T7 = perform a remote digital loopback test and self test &T8 = perform a local analog loopback test and self test &V displays configuration profiles &W_ &W0 = stores the modem's active configuration profile in stored configuration profile 0 &W1 = stores the modem's active configuration profile in stores configuration profile 1 &X_ &X0 = modem provides synchronous clock on EIA pin 15 &X1 = modem accepts an externally provided synchronous clock from the carrier detect signal being received and provides the clock on EIA pin 15 &Y_ &Y0 = designates configuration profile 0 to be the default configuration profile. When modem is turned on or reset, configuration profile 0 will be retieved as the active configuration profile &Y1 = designayes configuration profile 1 to be the default configuration profile. When modem is turned on or reset, configuration profile 1 will be retrieved as the active configuration profile &Zn stores up to 4 telephone numbers in the modem's non-volatile memory. Use DS=n to dial a number S-REGISTERS Default Register Range Value Function S0 0-255 rings 1 rings to auto-answer calls S1 0-255 rings 0 count number of incoming rings S2 0-127 ASCII 43 escape character S3 0-127 ASCII 13 carriage return character S4 0-127 ASCII 10 line feed character S5 0-32,127 ASCII 8 backspace character S6 0-255 seconds 2 dial tone wait time S7 1-255 seconds 30 wait time for remote carrier S8 1-255 14 delay time between loss of remote 1/10 seconds carrier and hangup S9 1-255 6 carrier detect response time 1/10 seconds S10 1-255 14 delay time between loss of remote 1/10 seconds carrier and hangup S11 50-255 95 duration and spacing of touch tones milliseconds S12 0-255 50 escape characters guard time 1/50 seconds S13 undefined S14 bitmapped echo, response, dialing and register originate/answer register S15 undefined S16 0, 1, 2, 4 0 modem tests S17 undefined S18 0-255 seconds 0 length of modem tests S19 undefined S20 undefined S21 bit-mapped jack, clear to send & data terminal register ready signals, and long space disconnect S22 bit-mapped speaker and response register register S23 bit-mapped 7 remote digital loopback request, data register rate, parity and guard tone register S24 not used S25 0-255 5 data terminal ready delay 1/100 seconds S26 0-255 seconds 1 request-to-send-to-clear to 1/100 seconds send delay fpr half-duplex operation S27 bit-mapped async/sync operation and line register register MODEM RESPONSES Word Number Responses Responses (V1 command) (V0 command) Meaning OK 0 modem successfully executed a command. Modem has switched from data mode to command mode CONNECT 1 data connection made with remote modem at any baud rate RING 2 modem has detected an incoming ring. Modem will only answer when given the A command, or when S0 is greater than 0 NO CARRIER 3 remote carrier signal lost or not detected within the time specified by S7; modem returns to command mode. ERROR 4 modem has found an error in your command line, and returns to command mode CONNECT 1200 5 modem has made a data connection at 1200 bps NO DIALTONE 6 with the W command, waits up to W command time; modem begins dialing as soon as dial tone is detected. when blind dialing, modem waits the S6 register time, then dials, regardless of whenther dial tone is detected BUSY 7 modem has detected a busy signal after dialing automatically NO ANSWER 8 you sent the Wait for Quiet Answer (@) command and the modem did not detect 5 secons silence CONNECT 2400 10 modem has made a data connection at 2400 bps