User guide

1892 1139 - RSX Range of Intelligent Modems User Guide - v7.1 / Nov 2007 25

3.2.3 Closing WinSetGMSK

To end the session with WinSetGMSK, click the X icon at the top right-hand corner of the

window.

If you have not saved changes to the modem parameters, you will be given the

opportunity before the program closes.

The unit returns to normal mode if it was in command mode.

3.3 CHANGING MODEM PARAMETERS USING SERIAL COMMANDS

We recommend using the WinSetGMSK software as an easy and reliable method of

programming modem features. However, it is also possible to use sequences of serial

commands from another source to do this. A standard terminal such as the VT100 can

send some, but not necessarily all, of the codes required.

Serial commands require the same connections as for data or WinSetGMSK.

In order to enter command mode, the RSXn50 must be in receive, not transmit mode, and

be sent the ASCII characters [escape]# – that is, two bytes of numerical value <27> and

<35>. These must be the first two characters since the unit went into receive mode. (This

may conveniently be arranged by lowering RTS briefly and raising it again.) When the

unit accepts the command, it responds with the characters [CR][LF].

Commands may then be given by sending a single-byte command code, sometimes

followed by a second parameter value byte, depending on the command. Parameter

bytes hold a numerical value between 0 and 255, not a character, and may therefore not

be available on a terminal. Commands and parameters are shown in the table. Each

successful command is responded to with [CR][LF].

To terminate command mode, send the command S (to save) or [escape] to cancel.

Modem Parameter or

Command

Byte

Parameter byte Notes

Char Value Decimal value

Source address a 97 0 to 255 Default is 10

Destination address b 98 0 to 255 Default is 10

RS232 baudrate d 100 0 to 7 0 = 9600

1 = 19200 (default)

2 = 300

3 = 600

4 = 1200

5 = 2400

6 = 4800

7 = 38400

Parity e 101 0, 1 or 2 0 = no parity

1 = odd parity

2 = even (default)

NOTE: The RSX works with 8 data bits + parity