
3COM CORPORATION

COURIER 1200

Modem Type             Data (synchronous/asynchronous)
Maximum Data Rate      1200bps
Data Bus               External
Data Modulation        Bell 103A/212A
Protocol

[Image]

                                CONNECTIONS

         Purpose             Location          Purpose           Location

  Line out                     CN2       DC power                  CN4

  Line in                      CN1       Power switch              SW1

  RS-232/422                   CN3

              DTR SIGNAL

  Setting                SW2/1

   On              DTR forced high

  Off                  DTR normal

                          RESULT CODES

  Setting                                    SW2/2

   Off                           Verbal result codes enabled

  On                             Numeric result codes enabled

          RESULT CODES DISPLAY

  Setting                  SW2/3

   On                Display enabled

  Off                Display disabled



            ECHO COMMANDS DISPLAY

  Setting                      SW2/4

   Off                  Local echo enabled

  On                    Local echo disabled

                                AUTO ANSWER

  Setting                                            SW2/5

   On                                Modem does not answer on first ring

  Off                                     Modem answers on first ring

           CARRIER DETECT

  Setting               SW2/6

  Off                 CD normal

   On             CD forced high

               MULTILINE PHONE INSTALLATION

  Setting                               SW2/7

   Off                         Single phone connected

  On                          Multiple phones connected

                      AT COMMAND SET

  Setting                               SW2/8

   On                        AT command set recognized

  Off                          AT command set disabled

                                ESCAPE CODE

  Setting                                           SW2/9

   On                                 Go to command mode and display OK
                                     result code when escape character is
                                                   received

  Off                                 Disconnect, go to command mode and
                                        display NO CARRIER when escape
                                            character is received

                                 DTR RESET

  Setting                                           SW2/10

   Off                                           DTR normal

  On                                  Reset 50ms after receiving DTR low
                                                   signal.

                       TX/RX PIN ASSIGNMENT

  Setting                                      SW3

   Off                                  Normal operation

  On                              Reverse TX/RX pin assignments



                             DIAGNOSTIC LED(S)

    LED         Color         Status                 Condition

     HS          Red            On         Modem is operating at 4800bps
                                                     or faster

     HS          Red           Off          Modem is operating at slower
                                                   than 4800bps

     AA          Red            On              Auto-answer enabled

     AA          Red           Off             Auto-answer disabled

     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

     RD          Red            On            Modem is receiving data

     RD          Red           Off          Modem is not receiving data

     TD          Red            On          Modem is transmitting data

     TD          Red           Off        Modem is not transmitting data

     TR          Red            On              DTR signal is high

     TR          Red           Off               DTR signal is low

     MR          Red            On                  Power is on

     MR          Red           Off                 Power is off

     AL          Red            On        Analog loopback self test mode

     AL          Red           Off               Normal operation

                         Proprietary AT Command Set

               See document V1254 for a full command summary.

