
POSITIVE CORPORATION

PC MODEM 2400S

Card Type               Modem(asynchronous)
Chip Set                Unidentified
Maximum Data Rate       2400bps
Data Bus                8 bit ISA
Data Modulation         Bell 103A/212A
Protocol
                        ITU-T V.21, V.22, V.22bis

[Image]

                                CONNECTIONS

         Function            Label            Function             Label

  Line in                         CN1       Line out                CN2

                     SERIAL PORT ADDRESS

       Setting                J2                  J3

     COM1 (3F8h)       Pins 2 & 3 closed   Pins 2 & 3 closed

     COM2 (2F8h)       Pins 2 & 3 closed   Pins 1 & 2 closed

     COM3 (3E8h)       Pins 1 & 2 closed   Pins 2 & 3 closed

     COM4 (2E8h)       Pins 1 & 2 closed   Pins 1 & 2 closed

                INTERRUPT

       Setting                J1

          2           Pins 1 & 2 closed

          3           Pins 1 & 3 closed

          4           Pins 1 & 4 closed

          5           Pins 1 & 5 closed

                         Proprietary AT Command Set

                          BIT-MAPPED REGISTER S14

  Format               AT [cmds] S14=n [cmds]

  Default:             170

  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:            16

  Range:              0 - 184

  Unit:               Bit-mapped.

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

   Bit      Value                          Function

    0            0    Not used.

    1            0    Not used.

    2            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    Not used.

    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           01   On volume

                  10   Medium level volume

                 11    High level volume

   3, 2           00   Speaker off

                  01   Speaker off until carrier detect

                  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 and dial
                       tone detection enabled
                 110
                       All result codes except dial tone detection
                111    enabled

                       All result codes enabled

     7            00   Make/break ratio 39%/61%

                 01    Make/break ratio 33%/67%

                          BIT-MAPPED REGISTER S23

  Format                AT [cmds] S23=n [cmds]

  Default:              7

  Range:                0-247

  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 disabled

                   1    Remote digital loopback enabled

   2, 1            00   Sets serial port speed to 0-300bps

                   01   Not used

                   10   Sets serial port speed to 1200bps

                  11    Sets serial port speed to 2400bps

     3             0    Not used

    5,4            00   Parity even

                   01   Space

                   10   Parity odd

                  11    No Parity

   7, 6            00   Guard tone disabled

                   01   Guard tone 550Hz enabled

                  10    Guard tone 1800Hz enabled

                                 PROTOCOL

  Format           AT [cmds] S27=n [cmds]

  Default:         32

  Range:           0 - 32

  Unit:            Bit-mapped

  Description:     Selects operating protocol

   Bit    Value                           Function

    0         0    Not used

    1         0    Not used

    2         0    Not used

    3         0    Not used

    4         0    Not used

    5         0    Not used

    6          0   CCITT V.22bis/V.22 enabled

              1    Bell 212 enabled

                                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 disabled

                1    Local analog loopback enabled

    1           0    Not used.

    2            0   Local digital loopback disabled

                1    Local digital loopback enabled

    3            0   Modem not in remote digital loopback.

                1    Remote digital loopback in progress.

    4            0   Remote digital loopback disabled

                1    Remote digital loopback enabled

    5            0   Remote digital loopback w/ self-test disabled

                1    Remote digital loopback w/ self-test enabled

    6            0   Local analog loopback w/ self-test disabled

                1    Local analog loopback w/ self-test enabled

