Chapter 5 - Error Correction, Data Compression, and Speed Conversion

5.12.3 Serial Port Baud Rate ($SB)

The $SB command presets the speed of the MT2834MR6’s RS-232 serial port in both the originate and the answer modes. Speed conversion allows you to set this serial port baud rate at a fixed speed of up to 115,200 bps, regardless of the modem’s transmission speed setting.It also sets the default speed at which the modem issues command responses (result codes).

For this command to work, the modem’s baud adjust feature must be turned off with the $BA command.

The MT2834MR6 will accept AT commands at any speed, regardless of the speed preset by the $SB command. If the modem receives such a command at a speed that is different from the preset speed, the modem switches its serial port baud rate to match the new AT command speed, although the baud rate value stored by the $SB command remains the same. This provides you with a convenient way to switch the serial port speed, while still making it easy to automatically return to the original speed the next time the modem is powered up, or reset using the ATZ command.

To set the serial port baud rate, type AT$SBn, where n can be 300, 1200, 2400, 4800, 9600,19,200, 38,400, 57,600, or 115,200 bps as listed below:

AT$SB300

300 bps

AT$SB1200

1200

bps

AT$SB2400

2400

bps

AT$SB4800

4800

bps

AT$SB9600

9600

bps

AT$SB19200

19200 bps

AT$SB38400

38400 bps

AT$SB57600

57,600 bps

AT$SB115200

115,200 bps (factory default)

 

 

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Multi-Tech Systems MT2834MR6 manual Serial Port Baud Rate $SB