                          Hayes 1200 compatible commands.

NOTE:  Not all commands may work on older Hayes models or "Hayes-compatible" 
       modems.  Attention prefix (AT) 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 a carriange return ([CR] [ENTER] [RETURN].


                                              ͻ
        COMMAND DESCRIPTION                    <2400> Commands 
                                              ͼ
        D       Dial
        P       Pulse dial
        T       Tone dial
        ,       Pause 
        !       Flash
        /       Wait for 1/8 sec.
        @       Wait for silence
        ;       Return to command state after dialing











NOTE: If a command accepts a numeric prefix, then the command with a 
      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.









NOTE:  Attention prefix (AT) precedes all command strings except +++ and A/.

        COMMAND DESCRIPTION

        A       Answer call without waiting for ring
        B       CCCIT V.22 mode
        B1      Bell 103 & 212A mode
        C       Transmit carrier off
        C1      Carrier on
        D       T         Tone dial
                P         Pulse dial
                R         Reverse mode (ans/orig)
                ,         Pause
                ;         Return to command state
        E       modem commands NOT echoed
        E1      modem commands 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
        COMMAND DESCRIPTION

        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       return to on-line state
        O1      Remote digital loopback off
        O2      Remote digital loopback request
        P       Pulse dial
        Q       Result codes displayed  *
        Q1      Result codes NOT displayed
        R       Reverse modem; call "originate only" modem
        Sr?     Requests current value of modem register 'r'
        Sr=n    Sets modem register 'r' to value 'n'
        T       Touch-tone dial
        V       Show digit result codes
        V1      Show word result codes
        X       Sets baudrate to 300, Smartmodem 300 compatibility mode










NOTE:  Attention prefix (AT) precedes all command strings except +++ and A/.

        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










                            R E S U L T   C O D E S


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



                            R E S U L T   C O D E S


Digit    Word         Description
-----    ----         --------------------------------------------------

  6      NO DIALTONE .Dial tone not detected; subsequent commands not
                      processed.  Results from X2 or X4 commands only.

  7      BUSY ........Busy signal detected and subsequent commands not pro-
                      cessed.  Results from X3 or X4 commands only.

  8      NO ANSWER ...Silence not detected and subsequent commands not pro-
                      cessed.  Results from @ cmd only.

add'l      6         DISCONNECT       Carrier has been lost

add'l      7         DIALING COMPLETE Modem ready to start dialing

add'l      8         RING RESPONSE    Number called is ringing


Ŀ
                           S   R E G I S T E R S                              
Ĵ
 Reg      Range      Unit      Description                                 
Ĵ
 S0    0-255        rings   Ring to answer telephone on                    
 S1    0-63/0-255   rings   Signal quality / number of rings               
 S2 !  0-127        ASCII   Hayes escape code character                    
 S3 !  0-127        ASCII   Carriage return character, usually 13 (0Dh)    
 S4 !  0-127        ASCII   Line feed character, usually 10 (0Ah)          
 S5 !  0-32,127     ASCII   Backspace character, usually 8 (08h)           
 S6    1-255         sec    Wait before blind dialing                      
 S7    1-255         sec    Wait time for carrier                          
 S8    0-255         sec    Pause time caused by comma                     
 S9    1-255       1/10sec  Carrier detect response time                   
 S10   1-255       1/10sec  Delay between loss of carrier and hangup       
 S11   20-255       msec    Duration and spacing of touch tones            
 S12!  1-255 *0.02 1/50sec  Hayes escape code guard time                   
 S13!  bit-mapped  Ĵ  UART status register                           
 S14!  bit-mapped            Option register *NOTE: The register numbers  * 
 S15!  bit-mapped            Flag register   *followed by an exclamation  * 
 S16!  0,1,2,4               Test modes      *point (!) should NOT change!* 

