2400 BPS Internal Modem (250-3524) Commands Faxback Doc. # 5038 BASIC COMMAND CODES ┌─────────┬────────────────┬─────────────────────────────────────────────────┐ │CODE │ DESCRIPTION │ FUNCTION │ ├─────────┼────────────────┼─────────────────────────────────────────────────┤ │ AT │Attention Code │ Every command line begins with AT (except the A/│ │ │ │ and +++ commands). Commands can be entered in │ │ │ │ lower or upper case, with spaces inserted for │ │ │ │ readability. Each command line must be termi- │ │ │ │ nated with the character stored in register S3 │ │ │ │ (default = carriage return). │ ├─────────┼────────────────┼─────────────────────────────────────────────────┤ │ A │Answer Command │ This command causes the modem to go off-hook and│ │ │ │ generate an answer carrier tone. Used for man- │ │ │ │ ual answer. │ ├─────────┼────────────────┼─────────────────────────────────────────────────┤ │ A/ │Repeat Last │ When this command is issued (without an AT pre- │ │ │Command │ fix) the last command entered is repeated. If │ │ │ │ the last command was a dial command and a con- │ │ │ │ nection was established, the last command will │ │ │ │ not be repeated. │ ├─────────┼────────────────┼─────────────────────────────────────────────────┤ │ENTER │Carriage Return │ Ends the command line and executes commands. Re-│ │ │ │ gister 3 defines the carriage return character. │ ├─────────┼────────────────┼─────────────────────────────────────────────────┤ │BACKSPACE│ BACKSPACE │ Deletes characters on the command line one by │ │ │ │ one. Register 5 defines the backspace character.│ ├─────────┼────────────────┼─────────────────────────────────────────────────┤ │ +++ │ Escape Code │ The command state in the modem can be entered │ │ │ │ during the on-line state by sending the escape │ │ │ │ sequence. The sequence consists of no trans- │ │ │ │ mission for the time specified by register S12, │ │ │ │ followed by three consecutive escape characters │ │ │ │ from register S2 and followed by another S12 re-│ │ │ │ gister time of no transmission. The default is:│ │ │ │ 1 second wait, +++, 1 second wait. The modem │ │ │ │ will respond with OK. │ ├─────────┼────────────────┼─────────────────────────────────────────────────┤ │ Z │ Reset Command │ This command resets the modem to its power up │ │ │ │ condition. Any connection present is broken. │ └─────────┴────────────────┴─────────────────────────────────────────────────┘ DIALING AND ANSWERING COMMANDS ┌───────────────┬─────────┬──────────────────────────────────────────────────┐ │ COMMAND │ DIALING │ FUNCTION │ ├───────────────┼─────────┼──────────────────────────────────────────────────┤ │ D │ Dialing │ Causes the modem to go off-hook and autodial the │ │ │ │ specified number using the specified parameters. │ ├───┬───────────┼─────────┼──────────────────────────────────────────────────┤ │ M │ P, T │ │ Select pulse or tone dialing. │ │ ├───────────┼─────────┼──────────────────────────────────────────────────┤ │ O │ , │ │ Pause for the time specified in register S8. │ │ │ │ │ (Default 2 seconds.) │ │ D ├───────────┼─────────┼──────────────────────────────────────────────────┤ │ │ ; │ │ Put the modem in the command state after dialing.│ │ I ├───────────┼─────────┼──────────────────────────────────────────────────┤ │ │ @ │ │ Wait for one or more rings followed by 5 seconds │ │ F │ │ │ of silence for the time specified in register S7.│ │ │ │ │ (Default = 30 seconds.) │ │ I ├───────────┼─────────┼──────────────────────────────────────────────────┤ │ │ ! │ │ Flash the modem on-hook for 1/2 second. │ │ E ├───────────┼─────────┼──────────────────────────────────────────────────┤ │ │ R │ │ Reverse the connection to answer instead of orig-│ │ R │ │ │ inate after dialing. │ │ ├───────────┼─────────┼──────────────────────────────────────────────────┤ │ S │ W │ │ Wait for dial tone. │ └───┴───────────┴─────────┴──────────────────────────────────────────────────┘ COMMANDS WITH PARAMETERS ┌────────┬────────────┬──────────────────────────────────────────────────────┐ │COMMAND │ PARAMETERS │ FUNCTION │ ├────────┼────────────┼──────────────────────────────────────────────────────┤ │ Bn │ 0 │ Selects CCITT V.22 operation when communicating at │ │ │ │ 1200 bps. │ │ │ 1 (Default)│ Selects BELL 103/212A operation when communicating at│ │ │ │ 1200 bps. │ ├────────┼────────────┼──────────────────────────────────────────────────────┤ │ En │ 0 │ Commands are not echoed │ │ │ 1 (Default)│ Commands are echoed. │ ├────────┼────────────┼──────────────────────────────────────────────────────┤ │ Hn │ 0 (Default)│ On hook (hang up). │ │ │ 1 │ Go off hook. │ ├────────┼────────────┼──────────────────────────────────────────────────────┤ │ In │ 0 │ Requests product identification code. │ │ │ 1 │ Performs checksum on firmware ROM; returns checksum. │ │ │ 2 │ Tests the modem's firmware ROM and memory; return OK │ │ │ │ or ERROR. │ ├────────┼────────────┼──────────────────────────────────────────────────────┤ │ Ln │ 0 │ Sets speaker volume to Low. │ │ │ 1 │ Sets speaker volume to Low. │ │ │ 2 (Default)│ Sets speaker volume to Medium. │ │ │ 3 │ Sets speaker volume to Maximum. │ ├────────┼────────────┼──────────────────────────────────────────────────────┤ │ Mn │ 0 │ Speaker off. │ │ │ 1 (Default)│ Speaker on until carrier detected. │ │ │ 2 │ Speaker always on. │ │ │ 3 │ Speaker on after dial until carrier detected. │ ├────────┼────────────┼──────────────────────────────────────────────────────┤ │ O │ │ The O command will cause the modem to return to the │ │ │ │ on-line state after the escape sequence has been │ │ │ │ entered. │ ├────────┼────────────┼──────────────────────────────────────────────────────┤ │ Qn │ 0 (Default)│ Modem returns result codes. │ │ │ 1 │ Modem does not return result codes. │ ├────────┼────────────┼──────────────────────────────────────────────────────┤ │ Sr │ │ The command Sr? will return the contents of the reg- │ │ │ │ ister r (values of r are from 0-27). When Sr=n is │ │ │ │ issued, register r is set to value n. │ ├────────┼────────────┼──────────────────────────────────────────────────────┤ │ Vn │ 0 │ Short form result codes │ │ │ 1 (Default)│ Long form result codes │ ├────────┼────────────┼──────────────────────────────────────────────────────┤ │ Xn │ 0 │ CONNECT MESSAGE: CONNECT │ │ │ │ DIALING: Wait for period in register S6 (default 2 │ │ │ │ seconds) and dial │ │ │ │ DIAL TONE: Ignored │ │ │ │ BUSY DETECT: No │ │ ├────────────┼──────────────────────────────────────────────────────┤ │ │ 1 │ CONNECT MESSAGE: Full messages │ │ │ │ DIALING: Wait for period in register S6 and dial │ │ │ │ DIAL TONE: Ignored │ │ │ │ BUSY DETECT: No │ │ ├────────────┼──────────────────────────────────────────────────────┤ │ │ 2 │ CONNECT MESSAGE: Full messages "CONNECT XXXX",XXXX is│ │ │ │ the bits per second rate. │ │ │ │ DIALING: Wait for dial tone │ │ │ │ DIAL TONE: Sensed │ │ │ │ BUSY DETECT: No │ │ ├────────────┼──────────────────────────────────────────────────────┤ │ │ 3 │ CONNECT MESSAGE: Full messages │ │ │ │ DIALING: Wait for period in register S6 and dial. │ │ │ │ DIAL TONE: Ignored │ │ │ │ BUSY DETECT: Yes │ │ ├────────────┼──────────────────────────────────────────────────────┤ │ │ 4 (Default)│ CONNECT MESSAGE: Full messages │ │ │ │ DIALING: Wait for dial tone │ │ │ │ DIAL TONE: Sensed │ │ │ │ BUSY DETECT: Yes │ ├────────┼────────────┼──────────────────────────────────────────────────────┤ │ Yn │ 0 (Default)│ Disables long space disconnect. │ │ │ 1 │ Causes the modem to disconnect when a space of 1.6 │ │ │ │ seconds or longer is received from the remote modem. │ └────────┴────────────┴──────────────────────────────────────────────────────┘ ADVANCED COMMANDS ┌────────┬────────────┬──────────────────────────────────────────────────────┐ │COMMAND │ PARAMETERS │ FUNCTION │ ├────────┼────────────┼──────────────────────────────────────────────────────┤ │ &Cn │ 0 │ DCD (Data Carrier Detect) always on. │ │ │ 1 (Default)│ DCD on indicates presence of data carrier. │ ├────────┼────────────┼──────────────────────────────────────────────────────┤ │ &Dn │ 0 │ Ignore DTR. │ │ │ 1 │ Switch to command mode when DTR goes from ON to OFF. │ │ │ 2 (Default)│ Switch to command mode and hang up when DTR goes from│ │ │ │ ON to OFF. │ │ │ 3 │ Reset modem (as in Z command) when DTR goes from ON │ │ │ │ to OFF. │ ├────────┼────────────┼──────────────────────────────────────────────────────┤ │ &Gn │ 0 (Default)│ Command disables the guard tone. │ │ │ 1 │ Selects a 550 Hz tone (for Europe). │ │ │ 2 │ Selects an 1800 Hz tone (for Europe). │ ├────────┼────────────┼──────────────────────────────────────────────────────┤ │ &Mn │ 0 (Default)│ Selects the asynchronous mode. │ │ │ 1 │ Causes the modem to go into synchronous mode when │ │ │ │ DTR is brought from OFF and ON. │ │ │ 3 │ Allows the call to be placed manually prior to en- │ │ │ │ abling the sync mode by bringing DTR from OFF to ON. │ ├────────┼────────────┼──────────────────────────────────────────────────────┤ │ &Pn │ 0 (Default)│ Sets the pulse dial make/break ratio = 39/61 (USA). │ │ │ 1 │ Sets the pulse dial make/break ratio = 33/67 (UK/HK).│ ├────────┼────────────┼──────────────────────────────────────────────────────┤ │ &Rn │ 0 (Default)│ In synchronous mode, causes CTS to follow RTS. │ │ │ 1 │ In synchronous mode, causes CTS to follow DCD (car- │ │ │ │ rier). │ ├────────┼────────────┼──────────────────────────────────────────────────────┤ │ &Sn │ 0 (Default)│ DSR (Data Set Ready) always on. │ │ │ 1 │ DSR operates in accordance with EIA RS-232C specifi- │ │ │ │ cations. │ ├────────┼────────────┼──────────────────────────────────────────────────────┤ │ &Tn │ 0 │ Terminate any currently active test. │ │ │ 1 │ Initiate local analog loopback (LAL) according to │ │ │ │ CCITT specifications. │ │ │ 3 │ Initiate local digital loopback (LDL). │ │ │ 4 │ Enable recognition of request from remote modem for │ │ │ │ remote digital loopback (RDL). │ │ │ 5 │ Prohibit recognition of remote request for RDL. │ │ │ 6 │ Initiate an RDL according to CCITT V.22bis (L2) │ │ │ │ specifications. │ │ │ 7 │ Initiate RDL with self-test. │ │ │ 8 │ Initiate LAL with self-test. │ └────────┴────────────┴──────────────────────────────────────────────────────┘ (smm 07/28/93)