HAYES COMMANDS, S REGISTERS, RS232C PIN-OUTS 1. AT Commands for the Hayes 1200B and Other Compatible Modems Not all commands may work on older Hayes models or on "Hayes-compatible" modems AT Attention prefix. Precedes all command strings except +++ and A/ A/ Repeat previous command line +++ Hayes escape code; switches from on-line state to command state. Allow 1 second pause before/after escape code entry. Do not follow with . DIALING COMMANDS D Dial P Pulse T Tone , Pause ! Flash / Wait for 1/8 sec. @ Wait for silence ; Return to command state after dialing OTHER COMMANDS (If a command accepts a numeric prefix, then the command with the sub-parameter 0 (zero) is the same as the command with NO numeric subparameter. For example, ATH0 is the same as ATH, ATM0 is the same as ATM, etc.) A Answer call without waiting for ring B CCITT V.22 mode B1 Bell 103 & 212A mode C Transmit carrier off C1 Carrier on E Characters NOT echoed E1 Characters echoed F Half-duplex F1 Full-duplex H On hook (hang up) H1 Off hook (line and auxiliary relay) H2 Off hook (line relay only) I Request product ID code (may be Hayes-specific) I1 Test ROM checksum I2 Test internal memory L0 Low speaker volume L1 Low speaker volume L2 Medium speaker volume L3 High speaker volume M Speaker always off M1 Speaker on until carrier detect M2 Speaker always on O Go to on-line state O1 Remote digital loopback off O2 Remote digital loopback request Q Result codes displayed Q1 Result codes NOT displayed Sr? Requests current value of modem register 'r' Sr=n Sets modem register 'r' to value 'n' V Show digit result codes V1 Show word result codes X Sets baudrate to 300 X1 Result code CONNECT 1200 enabled X2 Enables dial tone detection X3 Enables busy signal detection X4 Enables dial tone & busy signal detection Y Long space disconnect disabled Y1 Long space disconnect disabled Z Software reset; restore default settings 2. RESULT CODES Digit Word Description ----- ---- -------------------------------------------------- 0 OK ..........Command executed 1 CONNECT .....Connected at 300 or 1200 bps. Connected at 300 if result of X1, X2, X3 or X4 2 RING ........Ringing signal detected 3 NO CARRIER ..Carrier not detected or lost 4 ERROR .......Illegal cmd, error in cmd line, cmd line exceeds 40 chars, invalid char format at 1200 bps, invalid checksum 5 CONNECT 1200 Connected at 1200 bps. Results from X1, X2, X3 or X4 commands only 6 NO DIALTONE .Dial tone not detected; subsequent cmds not processed. Results from X2 or X4 cmds only. 7 BUSY ........Busy signal detected and subsequent cmds not pro- cessed. Results from X3 or X4 cmds only. 8 NO ANSWER ...Silence not detected and subsequent cmds not pro- cessed. Results from @ cmd only. 3. S REGISTERS Note: almost all have reasonable default values set by ATZ command Here is a list of the S-registers used by Hayes modem. Please be aware that not all modems support these registers and that some modems may have more registers than are listed. ALL S REGISTER COMMANDS ARE ENTERED IN THE AT COMMAND LINE. EXAMPLE: AT S8=2 S2=43 S7=30 TO READ THE VALUE IN ANY REGISTER USE AT SX? THE MODEM SHOULD ECHO THE VALUE FOUND IN THE REGISTER X REG Values Register function S0 0 AUTO ANSWER OFF 1-255 AUTO ANSWER ON, ANSWER ON INDICATED # OF RINGS S1 **0-255 RING COUNT (THIS IS A READ-ONLY REGISTER) S2 0-127 ESCAPE CHARACTER NORMALLY SET TO 43 OR "+" 127-255 ESCAPE FUNCTION DISABLED S3 0-127 END OF LINE CHARACTER NORMALLY SET TO 13 (CR) S4 0-127 LINE FEED CHARACTER NORMALLY SET TO 10 (LF) S5 0-127 BACKSPACE CHARACTER NORMALLY SET TO 8 (BS) S6 2-255 SEC PAUSE BEFORE DIALING (NORMALLY 2 SEC) S7 1-255 SEC WAIT FOR CARRIER (NORMALLY SET TO 30 SEC) S8 0-255 SEC PAUSE FOR COMMA IN DIAL STRING (NORMALLY SET TO 2 SEC) S9 1-255 .1SEC CARRIER VALIDATION TIME NORMALLY 6 (.6 SEC) S10 1-255 .1SEC LOSS OF CARRIER DISCONNECT DELAY NORMALLY 14 (1.4 SEC) S11 50-90 .1SEC BETWEEN NUMBER DIAL DELAY. UNDOCUMENTED. IMPROVE DIAL SPEED. I LIKE 55. THE DEFAULT IS 90. S12 20-255 .02SE ESCAPE SEQUENCE PAUSE NORMALLY 50 (1.0 SEC) S13 * POWER UP ASYNC DATA FORMAT (USE CHART BELOW) S14 * OPTION STATUS (USE CHART BELOW) S16 * TEST STATUS (USE CHART BELOW) S18 0-255 SEC TEST TIMER (REMOTE TEST) S21 * OPTION STATUS (USE CHART BELOW) S22 * OPTION STATUS (USE CHART BELOW) S23 * OPTION STATUS NORMALLY 07 (USE CHART BELOW) S25 0-255 SEC DTR DETECT DELAY NORMALLY 5 SEC ASYNC MODE, SYIC AUTO-DIAL AND SYIC MANUAL DIAL MODE .05 SEC S26 0-255 MS RTS TO CTS DELAY (1 MS) S27 * OPTION STATUS (USE CHART BELOW) * REGISTERS USED BY MODEM PROCESSOR. DO NOT ALTER THESE ** READ ONLY REGISTERS S 13 DATA FORMAT: POSITION VALUE FUNCTION BIT 0 - NOT USED BIT 1 - NOT USED BIT 2 0 PARITY OFF 1 PARITY ON BIT 3 0 ODD PARITY 1 EVEN PARITY BIT 4 0 7 DATA BITS 1 8 DATA BITS BIT 5 0 BIT 8=0 1 BIT 8=1 BIT 6 - NOT USED BIT 7 - NOT USED S 14 DATA FORMAT: BIT 0 - NOT USED BIT 1 0 LOCAL CHARACTER ECHO OFF 1 LOCAL CHARACTER ECHO ON BIT 2 0 STATUS DISPLAYS ON 1 STATUS DISPLAYS OFF BIT 3 0 STATUS CODES SENT 1 STATUS MESSAGES SENT BIT 4 0 MODEM RESPONDS TO COMMANDS 1 MODEM IGNORES COMMANDS BIT 5 0 TONE-DIALING 1 PULSE-DIALING BIT 6 - NOT USED BIT 7 0 ANSWER MODE 1 ORIGINATE MODE S 16 DATA FORMAT: BIT 0 0 ANALOG LOOP OFF 1 ANALOG LOOP ACTIVE BIT 1 - NOT USED BIT 2 0 DIGITAL LOOP OFF 1 DIGITAL LOOP ACTIVE BIT 3 0 REMOTE DIGITAL LOOP REQUESTED BY OTHER MODEM IS OFF 1 REMOTE DIGITAL LOOP REQUESTED BY OTHER MODEM IS ACTIVE BIT 4 0 REMOTE DIGITAL LOOP OFF 1 REMOTE DIGITAL LOOP ACTIVE BIT 5 0 SELF TEST RDL OFF 1 SELF TEST RDL ACTIVE BIT 6 0 SELF TEST ANALOG LOOP OFF 1 SELF TEST ANALOG LOOP ACTIVE BIT 7 - NOT USED S 21 DATA FORMAT: BIT 0 0 RJ11/RJ41/45 JACK TYPE 1 RJ12/FJ13 JACK TYPE BIT 1 - NOT USED BIT 2 0 CTS FOLLOWS RTS 1 CTS FORCED ON BIT 3&4 0 MODEM IGNORES DTR 1 MODEM ASSUMES COMMAND STATE WHEN DTR TURNS OFF 2 MODEM ASSUMES COMMAND STATE AND DISABLES AUTO-ANSWER WHEN DTR TURNS OFF 3 MODEM RESETS WHEN DTR TURNS OFF BIT 5 0 DCD FORCED ON 1 DCD FOLLOWS CARRIER BIT 6 0 DSR FORCED ON 1 DSR BEHAVES NORMALLY BIT 7 0 LONG SPACE DISCONNECT DISABLED 1 LONG SPACE DISCONNECT ENABLED S 22 DATA FORMAT: BIT 0&1 1 LOW SPEAKER VOLUME 2 MEDIUM SPEAKER VOLUME 3 HIGH SPEAKER VOLUME BIT 2&3 0 SPEAKER ALWAYS OFF 1 SPEAKER ON UNTIL CARRIER DETECTED 2 SPEAKER ALWAYS ON 3 SPEAKER OFF DURING DIALING THEN ON UNTIL CARRIER DETECTED BIT 4&5&6 0 X COMMAND IN EFFECT 4 X 1 COMMAND IN EFFECT 5 X 2 COMMAND IN EFFECT 6 X 3 COMMAND IN EFFECT 7 X 4 COMMAND IN EFFECT BIT 7 0 39/61 MAKE/BREAK RATIO (PULSE DIALING) 1 33/67 MAKE/BREAK RATIO S 23 DATA FORMAT: BIT 0 0 REMOTE DIGITAL LOOP REQUEST DENIED 1 REMOTE DIGITAL LOOP REQUEST GRANTED BIT 1&2 0 0-300 BPS 1 600 BPS 2 1200 BPS 3 2400 BPS BIT 3 - NOT USED BIT 4&5 0 EVEN PARITY 1 PARITY BIT ALWAYS 0 2 ODD PARITY 3 PARITY BIT ALWAYS 1 BIT 6&7 0 NO GUARD TONES 1 550 HZ GUARD TONE 2 1800 HZ GUARD TONE S 27 DATA FORMAT: BIT 0&1 0 ASYNCHRONOUS MODE 1 ASYNC/SYNC MODE 2 SYNC AUTO-DIAL 3 SYNC MANUAL DIAL BIT 2 0 PUBLIC PHONE LINE 1 LEASED LINE BIT 3 - NOT USED BIT 4&5 0 INTERNAL CLOCK USED 1 EXTERNAL CLOCK USED 2 SLAVED CLOCK USED BIT 6 0 CCITT V.22 PROTOCOL (1200 BPS) 1 BELL 212A (1200 BPS) BIT 7 - NOT USED Specialty Commands ATB0 CCITT V.22 AT 1200 BPS ATB1 BELL 212A AT 1200 BPS * AT &F RESTORE TO FACTORY CONFIGURATION AT &G NO GUARD TONE * AT &G1 550 HZ GUARD TONE AT &G2 1800 HZ GUARD TONE AT &J RJ11/RJ41S/RJ45 JACK * AT &J2 RJ12/RJ13 JACK AT &L REGULAR PHONE LINE * AT &L1 LEASED LINE AT &M ASYNC OPERATION * AT &M1 ASYNC/SYNC OPERATION AT &M2 SYNC AUTO DIAL AT &M3 SYNC MANUAL DIAL AT &P 39/61 PULSE MAKE/BREAK RATIO * AT &P1 33/67 PULSE MAKE/BREAK RATIO AT &T4 GRANT RDL TEST REQUEST * AT &T5 DENY RDL TEST REQUEST AT &W WRITE CURRENT REGISTERS TO NON-VOL-MEMORY (KEEP FOR POWER UP) AT &X SYNC CLOCK INTERNAL * AT &X1 SYNC CLOCK EXTERNAL AT &X2 SYNC CLOCK SLAVED AT &Z STORE DIAL COMMAND LINE DATA INTERFACE (2400) AT &C DCD ALWAYS ON * AT &C1 DCD ON WHILE CARRIER PRESENT AT &D DTR IGNORED * AT &D1 DTR FAIL DISCONNECT ENABLED (MODEM RETURNS TO COMMAND MODE) AT &D2 DTR FAIL DISCONNECT ENABLED (MODEM RETURNS TO COMMAND MODE, TURN AUTO ANSWER OFF) AT &D3 DTR FAIL DISCONNECT ENABLED (RESET MODEM) 4. RS 232 GENERAL PIN NOTES: (Compatibility) Most standard RS232 connector problems are with only several pins: (these are not the CBM pin numbers, but the DB25 Pins) Pins 2-3 swapped (TD/RD) (Also a null Modem Configuration) Pins 4-5-8 swapped, or tied together (RTS/CTS/DCD) Pins 6-20 swapped (DSR/DTR) Pins 1-7 tied together (Prot. Gnd/Sig Gnd) It should also be noted that most TELECOM failures result from cable problems, either intermittent, short or open. Some manufacturers do not solder the wires to the pins, but use crimp connectors. Pin 1; Protective Ground, to equipment frame. Further grounding may be required, depending upon regulation. (NEEDED) Pin 2; Transmitted Data. Generated by data terminal equipment going TO transmitting signal converter. (NEEDED) Pin 3; Received Data. Generated by the receiving signal converter going TO the data terminal equipment. (NEEDED) Pin 4; Request to Send. Line conditioner. On half-duplex controls the direction of data flow. (NEEDED) Pin 5; Clear to Send. Generated by the data communication equipment to flag if the data is or is not ready to be sent out. (NEEDED) Pin 6; Data Set Ready. Status of the Local Data Set (to terminal). Pin 8; Data Carrier Detect. Indicates if the receiving signal meets certain parameters. (to terminal) Pin 9; Plus Test Voltage Pin 10; Negative Test Voltage Pin 12; Secondary Line (DCD2) Pin 13; Secondary Line (CTS2) Pin 14; Secondary Line (TD2) Pin 15 & 17; T & R Timing Pin 16; Secondary Line (RD2) Pin 19; Secondary Line (RTS2) Pin 20; Data Terminal Ready (DTR) Controls switching the DCE to the communications channel. Pin 21; Signal Quality Detector. Indicates quality of signal (CCITT equiv. 110) (SQ) Pin 22; Ring Indicator (CCITT 125, circuit CE)((RI) Pin 23; Data Signal Rate Selector (for dual baud rate modems) Pin 24; Transmitter Signal Element Timing (for DTE) Pins 11, 18, and 25 are reserved or not used. Pin 7 is the needed Signal Ground, while pin 25 is sometimes used as a busy signal. Synchronous Data Transmissions usually use pins 15, 17 and 24 (clocks). A short note about standards: RS means Recommended Standard, by the EIA Specs. Two others 'standards' were designated by CCITT using the prefix V and X. Other RS standards are: 269B (synchronous rates); 334 (Signal Quality); 357 (FAX); 449 (37 Pin connectors) etc. This information was compiled from several sources, and should not be considered 'Official'. Always consult your modem/interface/computer manual for proper usage.