
MULTITECH SYSTEMS, INC.

MT2834PCS/C, MT2834PCS/CI

Modem Type                Data (synchronous/asynchronous)/Fax/Simultaneous
                          voice
Maximum Data Rate         28.8Kbps
Maximum Fax Rate          14.4Kbps
Data Bus                  External
Fax Class                 Class I & II
Data Modulation Protocol  Bell 103A/212A

                          ITU-T V.21, V.22, V.22bis, V.23, V.32, V.32bis,
                          V.34

                          AT&T V.32terbo

                          Multitech MSP
Fax Modulation Protocol   ITU-T V.17, V.21CH2, V.27ter, V.29
Error                     MNP2-5, V.42, V.42bis
Correction/Compression

[Image]

                                CONNECTIONS

         Purpose           Location            Purpose           Location

  Line in                     CN1       Line out                   CN2

                                      INTERRUPT SELECTION

  IRQ   JP1/A   JP1/B    JP1/C    JP1/D    JP1/E    JP1/F    JP1/G    JP1/H    JP1/I   JP1/J

  3     Open    Closed    Open     Open     Open    Open     Open     Open     Open     Open

  2/9   Closed   Open     Open     Open     Open    Open     Open     Open     Open     Open

  4     Open     Open    Closed    Open     Open    Open     Open     Open     Open     Open

  5     Open     Open     Open    Closed    Open    Open     Open     Open     Open     Open

  7     Open     Open     Open     Open    Closed   Open     Open     Open     Open     Open

  10    Open     Open     Open     Open     Open    Closed   Open     Open     Open     Open

  11    Open     Open     Open     Open     Open    Open     Closed   Open     Open     Open

  12    Open     Open     Open     Open     Open    Open     Open     Closed   Open     Open

  14    Open     Open     Open     Open     Open    Open     Open     Open     Closed   Open

  16    Open     Open     Open     Open     Open    Open     Open     Open     Open    Closed

                        BASE I/O ADDRESS SELECTION

  Address     SW1/1    SW1/2    SW1/3    SW1/4   SW1/5    SW1/6    SW1/7

    100h       Off      On       On       On       On       On       On

    200h       On       Off      On       On       On       On       On

    300h       Off      Off      On       On       On       On       On

    400h       On       On       Off      On       On       On       On

    500h       Off      On       Off      On       On       On       On

    2E8h       Off      On       Off      Off     Off       On      Off
  (COM4:)

    2F8h       Off      Off      Off      Off     Off       On      Off
  (COM2:)

    3D8h       Off      Off      On       Off     Off      Off      Off

    3E0h       On       On       Off      Off     Off      Off      Off

    3E8h       Off      On       Off      Off     Off      Off      Off
  (COM3:)

    3F0h       On       Off      Off      Off     Off      Off      Off

    3F8h       Off      Off      Off      Off     Off      Off      Off
  (COM1:)

       Note: A total of 127 memory base I/O address settings are
       available. The switches are a binary representation of the
       hexadecimal addresses. Switch SW1/1 is the Least Significant Bit
       and switch SW1/7 is the Most Significant Bit. The switches have
       the following decimal values: switch SW1/1=8, SW1/2=16, SW1/3=32,
       SW1/4=64, SW1/5=128, SW1/6=256, SW1/7=512.Turn off the switches
       and add the values of the off switches to obtain the correct base
       I/O address. (on=0, off=1)

  FACTORY CONFIGURED - DO NOT ALTER

      Switch            Position

       SW1/8               On

                          Proprietary Command Set

                         AMBIENT NOISE SENSITIVITY

  Type:           Configuration

  Format:         AT [cmds] >HVn [cmds]

  Example:        AT >HV10 >C0<CR>

  Default:        7

  Range:          0-14

  Description:    Sets the modems sensitivity to ambient noise, with 0
                  being the most sensitive.

                  AUTO-RELIABLE TIME BUFFER CONFIGURATION

  Type:          Configuration

  Format:        AT [cmds] $An [cmds]

  Example:       AT $A1 &W<CR>

  Description:   Controls the handling of incoming data during
                 auto-reliable time period.

    Command                              Function

      $A0        Data is discarded.

      $A1        Data is buffered.

                                 BIT MODE

  Type:          Configuration

  Format:        AT [cmds] $EBn [cmds]

  Example:       AT $EB1 E1<CR>

  Description:   Selects 10- or 11-bit mode.

    Command                              Function

      $EB0       Sets 10-bit mode.

      $EB1       Sets 11-bit mode.

                             CALLBACK ATTEMPTS

  Type:          Register

  Format:        AT [cmds] S16=n [cmds]

  Example:       ATS16=6<CR>

  Default:       4

  Range:         1-255

  Unit:          1 attempt

  Description:   Sets the maximum number of login attempts after initial
                 callback connection.

                              CALLBACK NUMBER

  Type:               Configuration

  Format:             AT [cmds] [+/-]DT<#>Nnn

  Examples:           AT#DB2 +-DT555-1212N10<CR>

  Description:        Sets the phone number associated with the password
                      at memory location nn.

       Command                             Function

         +DT          Modem will initiate callback on successful login.

         -DT          Modem will allow immediate entry on successful
                      login without callback.

        +-DT          If password is followed by a -, modem will allow
                      immediate entry. If password is followed by a + or
                      nothing, modem will initiate callback.

                              CALLBACK PARITY

  Type:          Configuration

  Format:        AT [cmds] #Pn [cmds]

  Example:       AT #P0 #DB1<CR>

  Description:   Sets the parity of the modem when in callback mode.

    Command                              Function

      #P0        No parity.

      #P1        Odd parity.

      #P2        Even parity.

                             CALLBACK PASSWORD

  Type:                Configuration

  Format:              AT [cmds] #CBNnnxxxx

  Example:             AT#DB2 #CBN09snarf<CR>

  Description:         Sets the callback password at memory location nn
                       to xxxx. The password must be between 6 and 10
                       characters, inclusive.

                             CALLBACK SECURITY

  Type:          Configuration

  Format:        AT [cmds] #DBn [cmds]

  Example:       AT #DB1 S0=1<CR>

  Description:   Sets the security level of the callback function.

    Command                              Function

      #DB0       Disables security and clears callback memory.

      #DB1       Enables remote security only.

      #DB2       Enables local and remote security.

                            COMMAND ESCAPE TYPE

  Type:          Configuration

  Format:        AT [cmds] %En [cmds]

  Example:       AT %E3 &W<CR>

  Description:   Sets type and response of command escape sequence.

    Command                              Function

      %E0        Command escape disabled.

      %E1        TIES escape (+++AT...)

      %E2        <BREAK>AT method.

      %E3        Both TIES and BREAK methods.

      %E4        OK response to command escape disabled.

      %E5        OK response to command escape enabled.

                                COMMAND SET

  Type:          Configuration

  Format:        AT &Qn

  Example:       AT &Q1<CR>

  Description:   Selects standard Hayes or custom command sets.

    Command                              Function

      &Q0        Multi-Tech custom command set enabled.

      &Q1        Standard Hayes command set enabled.

                                COMPRESSION

  Type:          Configuration

  Format:        AT &En

  Example:       AT &E15 #L0<CR>

  Description:   Selects data compression.

    Command                              Function

      &E14       Data compression disabled.

      &E15       Data compression enabled.

                             COMPRESSION MODE

  Type:          Configuration

  Format:        AT #Ln

  Example:       AT #L2 DT555-1212<CR>

  Description:   Selects active compression protocols.

    Command                              Function

      #L0        V.42 negotiation enabled.

      #L1        MNP negotiation enabled.

      #L2        LAP-M negotiation enabled.

      #L3        LAP-M enabled, no negotiation.

                                CTS SIGNAL

  Type:          Configuration

  Format:        AT [cmds] &RFn [cmds]

  Example:       AT &RF0<CR>

  Description:   Selects the function of the CTS signal.

    Command                              Function

      &RF0       CTS is set to RTS.

      &RF1       CTS is independent of RTS.

                              DETECTION MODE

  Type:          Configuration

  Format:        AT [cmds] >DTn [cmds]

  Example:       AT >DT1<CR>

  Description:   Sets the responses the modem will detect.

    Command                              Function

      >DT0       Detection disabled.

      >DT1       DTMF detection enabled.

      >DT2       All signals will be detected.

                         DIAL STORED PHONE NUMBER

  Type:                 Immediate

  Format:               AT [cmds] Nn1 [Nn2, Nn3...]

  Example:              ATM0 N1N3N5<CR>

  Description:          Dials stored phone number(s). If the first number
                        is busy, the modem will proceed to the next
                        number in the list.

                                 DSP INPUT

  Type:          Configuration

  Format:        AT [cmds] >DIn [cmds]

  Example:       AT >DI4 >DO6<CR>

  Description:   Sets the input source of the digital signal processor.

    Command                              Function

      >DI0       Input disabled.

      >DI1       Input from line in.

      >DI2       Input from handset.

      >DI3       Input from phone.

      >DI4       Input from PC.

      >DI5       Input from voicemail.

      >DI6       Input from Digital Simultaneous Voice Mode session.

                                DSP OUTPUT

  Type:          Configuration

  Format:        AT [cmds] >DOn [cmds]

  Example:       AT >DI5 >DO3<CR>

  Description:   Sets the output device of the digital signal processor.

    Command                              Function

      >DO0       Output disabled.

      >DO1       Output to line out.

      >DO2       Output to handset.

      >DO3       Output to phone.

      >DO4       Output to PC.

      >DO5       Output to voicemail.

      >DO6       Output to Digital Simultaneous Voice Mode session.

                                DSR SIGNAL

  Type:          Configuration

  Format:        AT [cmds] &SFn [cmds]

  Example:       AT &SF0<CR>

  Description:   Selects the function of the DSR signal.

    Command                              Function

      &SF0       DSR is set to CD.

      &SF1       DSR is independent of CD.

                         DSVD TALK ANYTIME&trade;

  Type:          Configuration

  Format:        AT [cmds] >Cn [cmds]

  Example:       AT >C1 O<CR>

  Description:   Enables DSVD (Digital Simultaneous Voice Data)
                 connection.

    Command                              Function

      >C0        Talk Anytime&trade; enabled.

      >C1        Talk Anytime&trade; disabled.

                                   DSVD

  Type:          Immediate

  Format:        AT [cmds] >VDn [cmds]

  Example:       AT >VD1 O<CR>

  Description:   Activates DSVD (Digital Simultaneous Voice Data)
                 connection.

    Command                              Function

      >VD0       Deactivates DSVD.

      >VD1       Activates DSVD.

                                DTR DIALING

  Type:          Configuration

  Format:        AT [cmds] $Dn [cmds]

  Example:       AT $D1 DT555-1212<CR>

  Description:   Turns DTR dialing on and off.

    Command                              Function

      $D0        DTR dialing disabled.

      $D1        DTR dialing enabled.

                                DTR TIMEOUT

  Type:          Register

  Format:        AT [cmds] S24=n [cmds]

  Example:       ATS24=40<CR>

  Default:       20

  Range:         0-255

  Unit:          50 ms

  Description:   Sets the time to drop the DTR signal to hangup.

                          ERASE CALLBACK PASSWORD

  Type:          Immediate

  Format:        AT [cmds] #RCBNn [cmds]

  Example:       AT #RCBN05 #RDN05<CR>

  Description:   Erases the callback password at the memory location
                 specified.

                           ERASE CALLBACK NUMBER

  Type:          Immediate

  Format:        AT [cmds] #RDNn [cmds]

  Example:       AT #RCBN05 #RDN05<CR>

  Description:   Erases the callback phone number at the memory location
                 specified.

                    ERROR CORRECTION DISABLE ON CONNECT

  Type:          Configuration

  Format:        AT [cmds] $Fn [cmds]

  Example:       AT $F1 DT555-1212<CR>

  Description:   Selects whether error correction can be disabled by a
                 <CR> while handshaking.

    Command                              Function

      $F0        Error correction handshake interrupt disabled.

      $F1        Error correction handshake interrupt enabled.

                        ESCAPE SEQUENCE BUFFER SIZE

  Type:          Register

  Format:        AT [cmds] S34=n [cmds]

  Example:       ATS34=30<CR>

  Default:       10

  Range:         0-60

  Unit:          1 byte

  Description:   Sets the size of the buffer used to store commands
                 during an escape sequence.

                       ESCAPE SEQUENCE - OUT OF BAND

  Type:          Immediate

  Format:        <BREAK> AT [cmds]<CR>

  Example:       <BREAK> AT #F1<CR>

  Description:   Puts the modem in Command Mode.

  Notes:         Do not precede this command with AT.

                 <BREAK> refers to the hardware modem break signal.

                          ESCAPE SEQUENCE TIMEOUT

  Type:              Register

  Format:            AT [cmds] S32=n [cmds]

  Example:           ATS32=30<CR>

  Default:           20

  Range:             0-255

  Unit:              1 second

  Description:       Sets the maximum amount of time the modem will wait
                     for a <CR> while executing an escape sequence.

                             FACTORY DEFAULTS

  Type:          Immediate/Configuration

  Format:        AT &F[n]

  Example:       AT &F8<CR>

  Description:   Loads factory defaults, or sets write protect on NVRAM.

    Command                              Function

       &F        Reloads defaults by setting. (Immediate, see below.)

      &F8        Sets &F to read factory defaults from ROM, and disables
                 NVRAM write protect.

      &F9        Sets &F to read defaults from NVRAM, and enables
                 write-protect.

                         FAILED PASSWORD ATTEMPTS

  Type:          Register

  Format:        AT [cmds] S26?

  Example:       ATS26?<CR>

  Default:       Read-only

  Range:         0-255

  Unit:          1 attempt

  Description:   This register stores the number of failed password
                 attempts.

                               FALLBACK MODE

  Type:          Configuration

  Format:        AT [cmds] #Fn [cmds]

  Example:       AT #F1 O<CR>

  Description:   Sets direction of fallback.

    Command                              Function

      #F0        Fallback disabled.

      #F1        Fallback from 28.8Kbps to 2400bps as line quality
                 degrades.

      #F2        Fallback from 2400bps to 28.8Kbps as line quality
                 improves.

                         FLOW CONTROL NORMAL MODE

  Type:          Configuration

  Format:        AT [cmds] &En [cmds]

  Example:       AT &E11 O<CR>

  Description:   Selects normal flow control.

    Command                              Function

      &E10       Normal mode disabled.

      &E11       Normal mode enabled.

                             FLOW CONTROL TYPE

  Type:          Configuration

  Format:        AT [cmds] &En [cmds]

  Example:       AT &E4 &W<CR>

  Description:   Sets type of flow control used by modem.

    Command                              Function

      &E3        Flow control disabled.

      &E4        CTS/RTS flow control enabled.

      &E5        XON/XOFF flow control enabled.

                            HANDSHAKE ATTEMPTS

  Type:                Configuration

  Format:              AT [cmds] #An [cmds]

  Example:             AT #A1 #L3<CR>

  Description:         Configures the initial handshake phase.

       Command                              Function

         #A0           Attempts in order: 28.8Kbps, 24Kbps, 21.6Kbps,
                       19.2Kbps, 16.8Kbps, 14.4Kbps, 12Kbps, 9600bps,
                       4800bps, 2400bps, 1200bps, 300bps.

         #A1           Attempts only 28.8Kbps.

         #A2           Attempts in order: 28.8Kbps, 24Kbps, 21.6Kbps,
                       19.2Kbps, 16.8Kbps, 14.4Kbps, 12Kbps, 9600bps,
                       4800bps.

         #A3           Attempts in order: 2400bps, 1200bps, 300bps.

                               HELP SCREENS

  Type:          Immediate

  Format:        AT $Hn

  Example:       AT $H1<CR>

  Description:   Shows modem help screens.

    Command                              Function

      $H1        Shows help screen 1.

      $H2        Shows help screen 2.

      $H3        Shows help screen 3.

                            LIST CONFIGURATION

  Type:          Immediate

  Format:        AT Ln

  Example:       AT L5<CR>

  Description:   Lists modem configuration.

    Command                              Function

       L5        Lists all settings.

       L6        Lists the values of all S-registers.

       L7        Lists extended parameters.

       L8        Lists current diagnostics.

                              LINE CONNECTION

  Type:          Configuration

  Format:        AT [cmds] >PHn [cmds]

  Example:       AT >PH1<CR>

  Description:   Selects the operation mode of the modem.

    Command                              Function

      >PH0       Modem is in data mode.

      >PH1       Modem is in voice mode.

                          LOCAL SERIAL PORT SPEED

  Type:          Configuration

  Format:        AT [cmds] $SBnnn [cmds]

  Example:       AT $MB9600 $SB19200<CR>

  Description:   Sets serial port speed.

    Command                              Function

     $SB300      Sets 300bps speed.

    $SB1200      Sets 1200bps speed.

    $SB2400      Sets 2400bps speed.

    $SB4800      Sets 4800bps speed.

    $SB9600      Sets 9600bps speed.

    $SB19200     Sets 19.2Kbps speed.

    $SB38400     Sets 38.4Kbps speed.

    $SB57600     Sets 57.6Kbps speed.

   $SB115200     Sets 115.2Kbps speed.

                             LOCK SERIAL PORT

  Type:          Configuration

  Format:        AT [cmds] $BAn [cmds]

  Example:       AT $SB57600 $BA0<CR>

  Description:   Sets operation of serial port speed.

    Command                              Function

      $BA0       Serial speed locked at rate set by $SB.

      $BA1       Serial speed follows connect speed, ignoring $SB.

                              LOGIN PASSWORD

  Type:                Configuration

  Format:              AT [cmds] #Ixxxx

  Example:             AT #IMicroHouse<CR>

  Description:         Sets the login password to xxxx. The password must
                       be between 6 and 10 characters, case sensitive. It
                       defaults to MULTI-TECH.

                    MAXIMUM BLOCK SIZE FOR TRANSMISSION

  Type:          Configuration

  Format:        AT [cmds] &BSn [cmds]

  Example:       AT &BS1 &MB28800<CR>

  Description:   Sets the maximum transmittable block size.

    Command                              Function

      &BS0       Maximum block size is 64 characters.

      &BS1       Maximum block size is 128 characters for LAP-M, and 256
                 characters for MNP.

                                MICROPHONE

  Type:          Configuration

  Format:        AT [cmds] >Mn>MVn [cmds]

  Example:       AT >M2>MV5<CR>

  Description:   Turns the microphone of the attached telephone handset
                 on or off.

  Note:          An >MV command must be issued on the same line.

    Command                              Function

      >M0        Disables microphone.

      >M2        Enables microphone.

                          MICROPHONE SENSITIVITY

  Type:          Configuration

  Format:        AT [cmds] >MVn [cmds]

  Example:       AT >MV6<CR>

  Default:       None

  Range:         0-14

  Description:   Sets the microphones sensitivity, with 0 being the most
                 sensitive.

                                 MSP MODE

  Type:          Configuration

  Format:        AT [cmds] >%Pn [cmds]

  Example:       AT >%P1<CR>

  Description:   Enables or disables Multitech Supervisory Protocol
                 (MSP).

    Command                              Function

      %P0        MSP disabled.

      %P1        MSP enabled.

                                  PACING

  Type:          Configuration

  Format:        AT [cmds] &En [cmds]

  Example:       AT &E13<CR>

  Description:   Selects ENQ/ACK pacing.

    Command                              Function

      &E12       Disables ENQ/ACK pacing.

      &E13       Enables ENQ/ACK pacing.

                             PACING - ENQ/ACK

  Type:          Configuration

  Format:        AT [cmds] &En [cmds]

  Example:       AT &E9<CR>

  Description:   Selects ENQ/ACK pacing.

    Command                              Function

      &E8        Enables ENQ/ACK pacing.

      &E9        Disables ENQ/ACK pacing.

                                  REDIAL

  Type:          Immediate

  Format:        ATA:

  Example:       ATA:<CR>

  Description:   Redials the last number dialed until it is no longer
                 busy.

                           REMOTE CONNECT SPEED

  Type:          Configuration

  Format:        AT $MBnnn

  Example:       AT $MB9600 $SB19200<CR>

  Description:   Sets maximum remote connect speed.

    Command                              Function

     $MB75       Sets V.23 (1200bps/75bps bi-directional).

     $MB300      Sets 300bps connect.

    $MB1200      Sets 1200bps connect.

    $MB2400      Sets 2400bps connect.

    $MB4800      Sets 4800bps connect.

    $MB9600      Sets 9600bps connect.

    $MB14400     Sets 14.4Kbps connect.

    $MB19200     Sets 19.2Kbps connect.

    $MB28800     Sets 28.8Kbps connect.

                          RETRANSMIT FAIL ACTION

  Type:          Configuration

  Format:        AT [cmds] $Rn [cmds]

  Example:       AT $R1<CR>

  Description:   Sets whether the modem gives up on a bad connection.

    Command                              Function

      $R0        Hang up after 12 failed retransmissions.

      $R1        Do not hang up after 12 failed retransmissions.

                          SETUP INACTIVITY TIMER

  Type:             Register

  Format:           AT [cmds] S29=n [cmds]

  Example:          ATS29=5<CR>

  Default:          20

  Range:            1-255

  Unit:             1 minute

  Description:      Sets the maximum amount of time between commands
                    until the setup password must be re-entered.

                                  SPEAKER

  Type:          Configuration

  Format:        AT [cmds] >Sn>SVn [cmds]

  Example:       AT >S2>SV5<CR>

  Description:   Turns the speaker of the attached telephone handset on
                 or off.

  Note:          An >SV command must be issued on the same line.

    Command                              Function

      >S0        Disables speaker.

      >S2        Enables speaker.

                              SPEAKER VOLUME

  Type:          Configuration

  Format:        AT [cmds] >SVn [cmds]

  Example:       AT >SV6<CR>

  Default:       None

  Range:         0-14

  Description:   Sets the speakers volume, with 0 being the most
                 sensitive.

                        STORE PHONE NUMBER IN NVRAM

  Type:          Configuration

  Format:        AT [cmds] D<#>Nn [dialstring]

  Example:       ATD555-1212N1<CR>

  Description:   Stores a phone number in the modems memory.

                       TIME UNTIL HANG UP ON LOW DTR

  Type:             Register

  Format:           AT [cmds] S36=n [cmds]

  Example:          ATS36=5<CR>

  Default:          0

  Range:            0-255

  Unit:             1 second

  Description:      Sets the maximum amount of time the modem will wait
                    to hang up after the DTR signal goes low.

                      TIME UNTIL PICK UP ON HIGH DTR

  Type:             Register

  Format:           AT [cmds] S37=n [cmds]

  Example:          ATS37=5<CR>

  Default:          0

  Range:            0-255

  Unit:             1 second

  Description:      Sets the maximum amount of time the modem will wait
                    to pick up after the DTR signal goes high.

                            TRELLIS MODULATION

  Type:          Configuration

  Format:        AT [cmds] #Tn [cmds]

  Example:       AT #T1<CR>

  Description:   Controls Trellis Coded Modulation.

    Command                              Function

      #T0        Disables TCM.

      #T1        Enables TCM.

                             V.32terbo CONTROL

  Type:          Configuration

  Format:        AT [cmds] #Vn [cmds]

  Example:       AT #V1 DT555-1212<CR>

  Description:   Controls the V.32terbo protocol in answer mode.

    Command                              Function

      #V0        V.32terbo enabled.

      #V1        V.32terbo disabled.

                                 V.42 MODE

  Type:          Configuration

  Format:        AT [cmds] &En [cmds]

  Example:       AT &E0 <CR>

  Description:   Configures the operation of V.42 mode.

    Command                              Function

      &E0        Error correction disabled.

      &E1        V.42 set to auto-reliable.

      &E2        V.42 set to reliable.

                              VOICE BANDWIDTH

  Type:            Configuration

  Format:          AT [cmds] >An [cmds]

  Example:         AT >A0 <CR>

  Description:     Sets the bandwidth reserved for voice transmission.

     Command                              Function

       >A0         Voice bandwidth set to 9600bps.

       >A1         Voice bandwidth set to 16Kbps.

       >A2         Voice bandwidth set to 16Kbps if connected at 19.2Kbps
                   or above, or 9600bps otherwise.

                                 XOFF SEND

  Type:          Configuration

  Format:        AT [cmds] #Xn [cmds]

  Example:       AT #X1<CR>

  Description:   Selects how XOFF signal is sent.

    Command                              Function

      #X0        Single XOFF character sent until ready.

      #X1        Multiple XOFF characters sent until ready.

                           XON/XOFF PASS-THROUGH

  Type:          Configuration

  Format:        AT [cmds] &En [cmds]

  Example:       AT &E7 O<CR>

  Description:   Selects whether XON/XOFF signals are sent to remote
                 modem.

    Command                              Function

      &E6        XON/XOFF signals trapped by local modem.

      &E7        XON/XOFF passed through local modem.

