Multi-Tech Systems BL-Series manual Auto Speed Detect #A

MultiModemBL User Guide

Auto Speed Detect #A

The function of the #A command is to detect and select the operational data rates (the “starting” speeds) with which the modem uses for initial handshake and speed selection.

Remember, this command does not control the originating data rate of the modem (that is done by the Modem Baud Rate command $MBn), but only the Answer mode “starting” speeds.

Entering AT#A0 (or AT#A) causes the modem to operate starting at:

2834 Series: 33,600 bps, with fallback to 28,800 to 19,200 to 14,400 to 9600 to 4800 to 2400 to 1200 and to 300 bps.

1932 Series: 19,200 bps, with fallback to 14,400 to 9600 to 4800 to 2400 to 1200 and to 300 bps.

1432 Series: 14,400 bps, with fallback to 9600 to 4800 to 2400 to 1200 and to 300 bps. Entering AT#A1 causes:

2834 Series: 33,600 bps operation only.

1932 Series: 19,200 bps operation only.

1432 Series: 14,400 bps operation only.

Entering AT#A2 causes the modem to operate at starting speeds of:

2834 Series: 33,600 bps, with incremental fallback to 28,800, 19,200, 14,400, 9600 and 4800 bps.

1932 Series: 19,200 bps, with incremental fallback to 14,400, 9600 and 4800 bps.

1432 Series: 14,400 bps, with incremental fallback to 29600 and 4800 bps.

The AT#A3 command causes the modem (all models) to begin operation as a V.22bis modem at 2400 bps, with fallback to 1200 to 300 bps. AT#A0 is the factory default value.

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