This addendum affects section 3.5 of the TCS-7700 operator’s Manual.

9.6 KBPS LOW-SPEED DATA CALL TO THE PSTN

To make a 9.6 data call, connect the DTE (Data Terminal Equipment) serial port to the asynchronous port on the MES (Mobile Earth Station) TSC-7700.

Note:
Use a RS-232 9 pin serial cable to connect to your TCS-7700 to your DTE.
Check that the LES selected on the TCS-7700 TCU, provides 9.6Kbps service.
Use a format of 8 data bits, no parity and one stop bit (8N1).

The 9.6 data port in located on the back of the TCU; it is a 9 pin female DIN connector, see fig 2.5.  Connect the 9.6 data port to any RS-232 interface. 

  The following instruction is used with your communication software in terminal mode.  Only such PC terminal programs that supports standard modem commands can be used for 9.6kbps data call.

MODEM AT COMMANDS

Using standard AT commands, you can request information, set parameters, and retrieve error messages.  Only some commands are listed here. All changes made while in terminal mode will be made to the next call.  The following are specific AT commands and are unique to the INMARSAT system

Table 1.  Specific AT command

Command

Response

Explanation

AT <Enter>

OK

Checks communication with modem.

AT+WRATE=? <Enter>

+WRATE=(9600),(1200-1400)

Returns all data rate supported by the MES in this order: (9600 supported satellite rate), (supported terrestrial rate).

AT+GCAP <Enter>

+GCAP:+W

OK

Gets a list of major classes of equipment supported by the MES.  In this case “+W” indicates wireless commands are supported.

AT+W <Enter>

“101”,”+WINMARSAT”

OK

MES indicates compliance with PCCA STD-101 and with the INMARSAT extension support

When a command “ERROR” message is displayed.  Type in “AT+WQ” to display the error message. 

Dialing Sequence

        Outgoing Data call.

        To establish a 9.6Kbps data call do the following.

        ATD0013015551000#<Enter>

        Incoming Data call

        Receiving a data call can be done manually or automatic.  Use the following commands as required:

        ATA<Enter>         (manual)

        ATS0=1<Enter>  (automatic)