============= 2400B HAYES MODEM COMMANDS LIST =============



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" commend line.

     Example: AT S8=2 S2=43 S7=30

To read the value in any register, use

         AT SX? <CR>

The modem should echo the value found in the regester 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 SEQENCE 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

S13 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

S14 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

S16 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

S21 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

S22 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

S23 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

S27 DATA FORMAT:
 BIT 0&1    0    ASYNCRONOUS 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
OTHER MODEM COMMANDS:
AT       STANDARD LEAD IN SEQUENCE (ATTENTION)
ATA      FORCE ANSWER
ATD      DIAL (ATD ###-#####)
   P     PULSE (ATDP ###-####)
   T     TONE  (ATDT ###-####)
ATE1     ENABLE LOCAL CHARACTER ECHO
ATE0     DISABLE LOCAL CHARACTER ECHO
ATH1     FORCE LINE CONNECT
ATH0     FORCE LINE DISCONNECT
ATI      ECHO VERSION TYPE
ATL1     SPEAKER VOLUME LOW
ATL2     SPEAKER VOLUME MEDIUM
ATL3     SPEAKER VOLUME HIGH
ATM0     SPEAKER ALWAYS OFF
ATM1     SPEAKER ON EXCEPT WHILE CARRIER PRESENT
ATM2     SPEAKER ALWAYS ON
ATM3     SPEAKER ON EXCEPT WHILE DIALING AND CARRIER PRESENT
ATO      GO ONLINE AFTER ESCAPE OR WHILE IN COMMAND MODE
ATQ0     STATUS DISPLAY ON
ATQ1     STATUS DISPLAY OFF
ATV0     STATUS MESSAGES SENT
ATV1     STATUS CODES SENT
ATX0     "CONNECT" (CODE 1)  ALL SPEEDS NO DIAL TONE DETECTION
ATX1     "CONNECT" (CODE 1)  0-300 BPS OR "CONNECT 1200" FOR 1200 OR
         "CONNECT 2400" FOR 2400 BPS NO DIAL TONE DETECTION
ATX2     WAIT FOR DIAL TONE (CONNECT SPEEDS SHOWN AS FOR X1)
ATX3     DETECT BUSY SIGNAL (CONNECT SPEEDS SHOWS AS FOR X1)
ATX4     WAIT FOR DIAL TONE, DETECT BUSY SIGNAL (CONNECT SPEEDS SHOWS AS FOR X1)

ATZ      RESET TO POWER UP CONDITION (CLEARS ALL REGISTERS)



2400 MODEM SPECIAL COMMANDS:    (* = FACTORY SETTING STANDARD)
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)


This information provided to you by David Scheall.  I can be reached at
CompuServ 71360,2662 or at GEnie by sending mail to address D.Scheall.
I hope you find this usefull!
