
MICROCOM, INC.

DESKPORTE 28.8S

Modem Type                   Data (synchronous/asynchronous)/Fax
Maximum Data Rate            28.8Kbps
Maximum Fax Rate             Unidentified
Data Bus                     External
Fax Class                    Unidentified
Data Modulation Protocol     Bell 103A/212A

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

                             Rockwell V.FC
Fax Modulation Protocol      Unidentified
Error Correction/Compression MNP5, MNP10, V.42, V.42bis

[Image]

                                CONNECTIONS

         Purpose             Location          Purpose           Location

  Line out                     CN1       DC power                  CN4

  Line in                      CN2       Power switch              SW1

  RS-232/422                   CN3

                             DIAGNOSTIC LED(S)

    LED         Color         Status                 Condition

     AA          Red            On              Auto-answer enabled

     AA          Red           Off             Auto-answer disabled

     RD          Red            On            Modem is receiving data

     RD          Red           Off          Modem is not receiving data

     SD          Red            On          Modem is transmitting data

     SD          Red           Off        Modem is not transmitting data

     CD          Red            On            Carrier signal detected

     CD          Red           Off          Carrier signal not detected

     OH          Red            On               Modem is off-hook

     OH          Red           Off               Modem is on-hook

     TR          Red            On              DTR signal is high

     TR          Red           Off               DTR signal is low

     TM          Red            On               Test mode enabled

     TM          Red           Off              Test mode disabled

     TM          Red        Slow blink            RAM test failed

     TM          Red       Medium blink           ROM test failed

     TM          Red        Fast blink      MDP(Data Pump) test failed

                         Proprietary AT Command Set

                    AUTO-RETRAIN - FALLBACK/FALLFORWARD

  Type:          Configuration

  Format:        AT [cmds] %En [cmds]

  Description:   Controls auto-retrain mode and fallback/fall forward

    Command                              Function

      %E0        Auto-retrain disabled

      %E1        Auto-retrain enabled

   %E2          Fallback/fall forward enabled

      %E3        Auto-retrain enabled, modem will hang up if EQM reaches
                 hang up threshold

                          BIT-MAPPED REGISTER S14

  Format                   AT [cmds] S14=n [cmds]

  Default:                 138

  Range:                   0-174

  Unit:                    Bit-mapped

  Description:             Controls echo, result codes, result code
                           display, dial mode, and answer/originate mode

       Bit          Value                      Function

        0             0       Not used

        1             0       Command echo disabled

                   1         Command echo enabled

        2          0         Result codes enabled

                      1       Result codes disabled

        3             0       Display result codes in numeric format

                   1         Display result codes in verbose format

        4             0       Not used

        5          0         Tone dial enabled

                      1       Pulse dial enabled

        6             0       Not used

        7             0       Answer mode enabled

                   1         Originate mode enabled

                          BIT-MAPPED REGISTER S21

  Format                   AT [cmds] S21=n [cmds]

  Default:                 0

  Range:                   0-248

  Unit:                    Bit-mapped

  Description:             Selects low DTR action, DCD signal, DSR
                           signal, and the Long Space Disconnect function

       Bit          Value                       Function

      2 - 0           0        Not used

      4, 3          00        DTR signal ignored

                      01       Modem goes to command mode on low DTR

                      10       Modem disconnects on low DTR Auto-Answer
                               is disabled
                      11
                               Modem is initialized on low DTR

        5           0         DCD forced high

                      1        DCD normal

        6           0         DSR forced high

                      1        DSR normal

        7           0         Long Space Disconnect function disabled

                      1        Long Space Disconnect function enabled

                          BIT-MAPPED REGISTER S22

  Format                    AT [cmds] S22=n [cmds]

  Default:                  117

  Range:                    0-127

  Unit:                     Bit-mapped

  Description:              Controls speaker volume and controls, and
                            limits results codes

       Bit           Value                      Function

       1, 0            00       Off volume

                     01        Low level volume

                       10       Medium level volume

                       11       High level volume

       3, 2            00       Speaker off

                     01        Speaker off on carrier

                       10       Speaker always on

                       11       Speaker on during handshake

     6, 5, 4           000      Basic result codes only enabled

                       100      Basic and connection speed result codes
                                enabled
                       101
                                Basic and connection speed result codes
                       110      and dialtone detection enabled

                     111       All result codes except dialtone
                                detection enabled

                                All result codes enabled

                          BIT-MAPPED REGISTER S23

  Format                   AT [cmds] S23=n [cmds]

  Default:                 55

  Range:                   0-189

  Unit:                    Bit-mapped

  Description:             Grants/denies remote digital loopback,
                           controls DTE rate and parity, and sets guard
                           tone

       Bit            Value                     Function

        0               0       Remote digital loopback denied

                     1         Remote digital loopback allowed

     3, 2, 1           000      Sets serial port speed to 0-300bps

                       001      Sets serial port speed to 600bps

                       010      Sets serial port speed to 1200bps

                     011       Sets serial port speed to 2400bps

                       100      Sets serial port speed to 4800bps

                       101      Sets serial port speed to 9600bps

                       110      Sets serial port speed to 19200bps

       5,4              00      Parity even

                        01      Not used

                        10      Parity odd

                     11        No Parity

       7, 6          00        Guard tone disabled

                        01      Guard tone disabled

                       10       Guard tone 1800Hz enabled

                          BIT-MAPPED REGISTER S27

  Format                    AT [cmds] S27=n [cmds]

  Default:                  73

  Range:                    0-73

  Unit:                     Bit-mapped

  Description:              Selects sync/async mode and ITU-T/Bell modes

       Bit           Value                      Function

     3, 1, 0           000      Asynchronous mode, serial port speed
                                follows connect speed
                     101
                                Error correction mode

     5, 4, 2           0        Not used

        6               0       CCITT mode

                     1         Bell mode

                          BIT-MAPPED REGISTER S28

  Format                AT [cmds] S28=n [cmds]

  Default:              0

  Range:                0-128

  Unit:                 Bit-mapped

  Description:          Controls pulse dialing and MNP10 link negotiation

     Bit         Value                        Function

    2 - 0          0       Not used

     4, 3        00       39ms make/61ms break at 10pps

      5            0       Not used

     7, 6        00       Link will be negotiated at highest possible
                           speed
                   01
                           Link will be negotiated at 1200bps
                   10
                           Link will be negotiated at 4800bps

                          BIT-MAPPED REGISTER S31

  Format                AT [cmds] S31=n [cmds]

  Default:              2

  Range:                0-10

  Unit:                 Bit-mapped

  Description:          Controls auto-baud function and result codes

     Bit         Value                        Function

      0            0       Not used

      1             0      Auto-baud disabled

                 1        Auto-baud enabled

     3, 2        00       DTE speed displayed in result codes

                   01      Extended result codes enabled; DCE speed
                           displayed in result codes.
                   10
                           DCE speed displayed in result codes

                          BIT-MAPPED REGISTER S40

  Format                    AT [cmds] S40=n [cmds]

  Default:                  105

  Range:                    0-239

  Unit:                     Bit-mapped

  Description:              Controls power level and break handling;
                            selects MNP extended services, link
                            negotiation, and block size

        Bit           Value                     Function

       1, 0             00       MNP10 disabled

                      01        MNP10 enabled

                        10       MNP10 enabled on originate mode only

         0               0       MNP10 disabled

                      1         MNP10 enabled

         1               0       MNP10 at 2400 and 1200bps disabled

                      1         MNP10 at 2400 and 1200bps enabled

         2            0         Power level adjustment disabled

                        1        Power level adjustment enabled

      5, 4, 3           000      \K0

                        001      \K1

                        010      \K2

                        011      \K3

                        100      \K4

                      101       \K5

       7, 6             00       MNP block size is 64 characters

                      01        MNP block size is 128 characters

                        10       MNP block size is 192 characters

                        11       MNP block size is 256 characters

                          BIT-MAPPED REGISTER S41

  Format                  AT [cmds] S41=n [cmds]

  Default:                195

  Range:                  0-223

  Unit:                   Bit-mapped

  Description:            Selects compression, auto-retrain, flow
                          control, MNP mode, and fallback-V.22/22bbis

       Bit         Value                       Function

      1 - 0          00      Data compression disabled

                     01      MNP5 enabled

                     10      V.42bis enabled

                   11       MNP5 and V.42bis enabled

      6, 2           00      Auto-retrain disabled

                     01      Auto-retrain enabled

                   10       Fallback/fall forward enabled

                     11      Auto-retrain enabled, modem will hang up if
                             EQM reaches hang up threshold

        3          0        Flow control disabled

                     1       Flow control enabled

        4          0        Stream mode for MNP

                     1       Block mode for MNP

        5            0       Not used

        7             0      MNP10 at 2400 and 1200bps disabled

                   1        MNP10 at 2400 and 1200bps enabled

                                BREAK SEND

  Type:          Configuration

  Format:        AT [cmds] \Bn [cmds]

  Default:       3

  Range:         1-9

  Unit:          .1 second

  Description:   Sends break to modem

                                BREAK TYPE

  Type:           Configuration

  Format:         AT [cmds] \Kn [cmds]

  Description:    Configures action of break signal

     Command         Break from DTE     Break from DTE       Break from
                                                           remote modem
                    Reliable/Normal      Direct mode
                         mode

       \K0         Enter command       Send break to      Buffers cleared
                   mode, do not send   remote modem       and break sent
                   break to remote     immediately,       to DTE
                   modem               then enter
                                       command mode

       \K1         Buffers cleared     Send break to      Buffers cleared
                   and break sent to   remote modem       and break sent
                   remote modem        immediately,       to DTE
                                       then enter
                                       command mode

       \K2         Enter command       Send break to      Send break to
                   mode, do not send   remote modem       DTE immediately
                   break to remote     immediately
                   modem

       \K3         Send break to       Send break to      Send break to
                   remote modem        remote modem       DTE immediately
                   immediately         immediately,
                                       then enter
                                       command mode

       \K4         Enter command       Send break to      Break sent with
                   mode, do not send   remote modem       received data
                   break to remote     immediately        to the DTE
                   modem

   \K5            Send break with     Send break to      Break sent with
                   transmitted data    remote modem       received data
                                       immediately        to the DTE

                        CELLULAR TRANSMISSION LEVEL

  Type:          Configuration

  Format:        AT [cmds] @Mn [cmds]

  Default:       0

  Range:         11-31

  Unit:          -1dBm

  Description:   Sets the signal level for transmission

    Command                              Function

      @M0        -26dBm

      @M1        -30dBm

    @M2-@M10     -10dBm

                        CELLULAR TRANSMISSION LEVEL

  Format               AT [cmds] S201=n [cmds]

  Default:             58

  Range:               0-63

  Unit:                Bit-mapped

  Description:         Controls cellular transmission level and
                       compromise equalizer

     Bit         Value                        Function

    4 - 0        00000     Sets cellular transmit level level to -26dBm

                 00001     Sets cellular transmit level level to -30dBm

                 00010     Sets cellular transmit level level to -10dBm

                  ...      ...

                 01010     Sets cellular transmit level level to -10dBm

                 01011     Sets cellular transmit level level to -11dBm

                  ...      ...

                 11010    Sets cellular transmit level level to -26dBm

                  ...      ...

                 11111     Sets cellular transmit level level to -31dBm

      5            0       Equalizer disabled

                 1        Equalizer enabled

                             CHANGE DIAL CODES

  Type:          Configuration

  Format:        AT [cmds] *Zn [cmds]

  Description:   Selects dial codes, for International use

    Command                              Function

      *Z0        Enable dial code 0

      *Z1        Enable dial code 1

                                COMPRESSION

  Type:          Configuration

  Format:        AT [cmds] %Cn [cmds]

  Description:   Selects data compression

    Command                              Function

      %C0        Data compression disabled

      %C1        MNP5 enabled

      %C2        V.42bis enabled

   %C3          MNP5 and V.42bis enabled

                           COMPROMISE EQUALIZER

  Type:          Configuration

  Format:        AT [cmds] :En [cmds]

  Description:   Controls V.32 compromise equalizer

    Command                              Function

      :E0        Equalizer disabled

   :E1          Equalizer enabled

                               CONNECT MODE

  Type:          Configuration

  Format:        AT [cmds] \Nn [cmds]

  Description:   Sets connect mode

    Command                              Function

      \N0        Normal mode enabled

      \N1        Direct mode enabled

      \N2        Reliable mode enabled

   \N3          Auto-reliable mode enabled

      \N4        LAPM mode enabled

      \N5        MNP mode enabled

                                   DIAL

  Type:                 Immediate

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

  Description:          Dials telephone number according to any modifiers
                        included in the string

       Modifier                             Function

          J             Link will be negotiated at 1200bps

          K             Power level adjustment enabled

          L             Redials last valid dial string

          P             Pulse dialing enabled

         S=c            Number in memory location c dialed

          T             Tone dialing enabled

          W             Dialing resumed following dial tone detection

          @             Modem waits for a ring-back signal followed by
                        silence up to the time specified in S7 prior to
                        executing the rest of the dial string.

          !             Flash function initiated Modem commanded to go
                        on-hook for specified time

          ;             Modem returned to command mode after dialing

          ^             Disable calling tone

          &             Detect bong tone. Modem waits for time specified
                        in S6 before returning NO DIALTONE.

                          DISPLAY STORED NUMBERS

  Type:          Immediate

  Format:        AT [cmds] \F [cmds]

  Description:   Displays all stored phone numbers

                               FLOW CONTROL

  Type:          Configuration

  Format:        AT [cmds] \Gn [cmds]

  Description:   Selects modem port flow control

    Command                              Function

   \G0          Flow control disabled

      \G1        Flow control enabled

                       FLOW CONTROL CHARACTER - XOFF

  Type:          Register

  Format:        AT [cmds] S33=n [cmds]

  Default:       19

  Range:         0-255

  Unit:          ASCII

  Description:   Sets the character used to represent XOFF.

                       FLOW CONTROL CHARACTER - XON

  Type:          Register

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

  Default:       17

  Range:         0-255

  Unit:          ASCII

  Description:   Sets the character used to represent XON.

                             LINE SIGNAL LEVEL

  Type:          Immediate

  Format:        AT [cmds] %L [cmds]

  Range:         9-43

  Unit:          -1dBm

  Description:   Displays received line signal level

                           MNP STREAM/BLOCK MODE

  Type:          Configuration

  Format:        AT [cmds] \Ln [cmds]

  Description:   Selects the transfer mode for MNP

    Command                              Function

   \L0          Stream mode for MNP enabled

      \L1        Block mode for MNP enabled

                             MNP10 COMPRESSION

  Type:          Configuration

  Format:        AT [cmds] -Kn [cmds]

  Description:   Selects MNP10 data compression

    Command                              Function

      -K0        MNP10 disabled

   -K1          MNP10 enabled

      -K2        MNP10 enabled on originate mode only

                    MAXIMUM BLOCK SIZE FOR TRANSMISSION

  Type:          Configuration

  Format:        AT [cmds] \An [cmds]

  Description:   Sets the maximum transmittable block size

    Command                              Function

      \A0        MNP block size is 64 characters

   \A1          MNP block size is 128 characters

      \A2        MNP block size is 192 characters

      \A3        MNP block size is 256 characters

                              MNP10 FALL-BACK

  Type:          Configuration

  Format:        AT [cmds] -Qn [cmds]

  Description:   Allows MNP10 to fall back to speeds slower than 4800bps

    Command                              Function

      -Q0        MNP10 at 2400 and 1200bps disabled

   -Q1          MNP10 at 2400 and 1200bps enabled

                          MNP10 LINK NEGOTIATION

  Type:          Configuration

  Format:        AT [cmds] *Hn [cmds]

  Description:   Sets the speed at which MNP10 link negotiation will
                 occur

    Command                              Function

   *H0          Link will be negotiated at highest possible speed

      *H1        Link will be negotiated at 1200bps

      *H2        Link will be negotiated at 4800bps

  Note: *H2 not supported with )M1

                         MNP10 POWER LEVEL ADJUST

  Type:           Configuration

  Format:         AT [cmds] )Mn [cmds]

  Description:    Controls automatic transmit power level adjustment
                  during MNP 10 link negotiation

    Command                              Function

   )M0           Power level adjustment disabled

      )M1         Power level adjustment enabled

  Note: )M1 not supported with *H2

                       MODULATION SELECTION DISPLAY

  Type:          Immediate

  Format:        AT [cmds] +MSUnidentified [cmds]

  Description:   Displays modulation, automode, minimum rate and maximum
                 rate settings

                           MODULATION SELECTION

  Type:                Configuration

  Format:              AT [cmds] +MS=xx,y,zzz,aaa [cmds]

  Description:         Sets options for active protocol. The transfer
                       rates specified by z and a must be valid for the
                       protocol selected

       Command                              Function

         x=0           V.21

         x=1           V.22

         x=2           V.22bis

         x=3           V.23

         x=9           V.32

        x=10           V.32bis

   x=11               V.34

        x=64           Bell 103A

        x=69           Bell 212A

        x=74           V.FC

         y=0           Automode disabled

   y=1                Auto-detect highest speed enabled

   z, a=300           Set minimum or maximum transfer rate at 300bps,
                       respectively

      z, a=1200        Set minimum or maximum transfer rate at 1200bps,
                       respectively

      z, a=2400        Set minimum or maximum transfer rate at 2400bps,
                       respectively

      z, a=4800        Set minimum or maximum transfer rate at 4800bps,
                       respectively

      z, a=7200        Set minimum or maximum transfer rate at 7200bps,
                       respectively

      z, a=9600        Set minimum or maximum transfer rate at 9600bps,
                       respectively

     z, a=12000        Set minimum or maximum transfer rate at 12000bps,
                       respectively

     z, a=14400        Set minimum or maximum transfer rate at 14400bps,
                       respectively

     z, a=16800        Set minimum or maximum transfer rate at 16800bps,
                       respectively

     z, a=19200        Set minimum or maximum transfer rate at 19200bps,
                       respectively

     z, a=21600        Set minimum or maximum transfer rate at 21600bps,
                       respectively

     z, a=24000        Set minimum or maximum transfer rate at 24000bps,
                       respectively

     z, a=26400        Set minimum or maximum transfer rate at 26400bps,
                       respectively

   z, a=28800         Set minimum or maximum transfer rate at 28800bps,
                       respectively

                            REPORT INFORMATION

  Type:            Immediate

  Format:          AT [cmds] In [cmds]

  Description:     Displays modem properties

     Command                              Function

       I0          Reports OK

       I1          Performs checksum of firmware ROM and displays results

       I2          Performs checksum of firmware ROM and displays status
                   (OK or ERROR)

       I3          Reports firmware version, model code, interface type,
                   and MCU model

       I4          Reports identifier string

       I5          Reports country code

       I6          Reports modem data pump model, internal code revision
                   and CEP internal code revision.

                        REPORT LINE SIGNAL QUALITY

  Type:            Immediate

  Format:          AT [cmds] %Q [cmds]

  Description:     Reports line signal quality. If the value is greater
                   than 7, the modem will retrain.

                                SLEEP TIMER

  Format                  AT [cmds] S24=n [cmds]

  Default:                0

  Range:                  0-255

  Unit:                   1 second

  Description:            Maximum duration of DTE and DCE inactivity
                          allowed prior to initiating low-power sleep
                          mode.

                                TEST MODES

  Format                 AT [cmds] S16=n [cmds]

  Default:               0

  Range:                 0-125

  Unit:                  Bit-mapped

  Description:           Controls loopback tests, analog, digital, remote
                         digital, and self tests

      Bit         Value                        Function

       0             0       Local analog loopback not in progress

                    1        Local analog loopback in progress

     2, 1           0        Not used

       3             0       Modem not in remote digital loopback

                    1        Remote digital loopback in progress

       4             0       Remote digital loopback not requested

                    1        Remote digital loopback requested

       5             0       Remote digital loopback w/ self-test not in
                             progress
                    1
                             Remote digital loopback w/ self-test in
                             progress

       6             0       Local analog loopback w/ self-test not in
                             progress
                    1
                             Local analog loopback w/ self-test in
                             progress

                           V.23 SPLIT BAUD MODE

  Type:          Configuration

  Format:        AT [cmds] \Wn [cmds]

  Description:   Controls V.23 split baud mode

    Command                              Function

   \W0          V.23 split baud mode disabled

      \W1        V.23 split baud mode enabled

                        V.23 SPLIT-SPEED DIRECTION

  Type:          Configuration

  Format:        AT [cmds] %Fn [cmds]

  Description:   Selects flow control

    Command                              Function

      %F1        75bps transmit/1200bps receive enabled

      %F2        75bps receive/1200bps transmit enabled

