MultiModemDSVD User Guide

4 AT Commands, S-Registers, and Result Codes

Command: +MS=

Modulation Selection

Values:

See description.

Default:

See description.

Description:

This extended-format command selects modulation and, op-

 

tionally, enables or disables automode, specifies the lowest and

 

highest connection rates, selects µ-Law or A-Law codec type,

 

and specifies the highest transmit rate using one to five

 

subparameters.

The command format is

+MS=[mod][,[automode][,[min_RX_rate][,[max_RX_rate][,[x_law] [,[reserved][,[max_TX_rate]]]]]]]<CR>

Subparameters that are not entered retain their current value. Commas separate optional subparameters, and should be inserted to skip a subparameter. Example: +MS=,0,<CR> disables automode and keeps all other settings at their current values.

+MS? Reports current options in the format mod,automode,min_RX_rate,max_RX_rate,x_law,reserved,max_TX_rate. Example: 56,1,300,56000,0,0,33600.

+MS=? Reports supported options in the format (list of supported mod values),(list of supported automode values),(list of supported min_RX_rate values),(list of supported max_RX_rate values), (list of supported x_law values), (list of supported reserved values),(list of supported max_TX_rate values).

Example: (0,1,2,3,9,10,11,56,64,69),(0,1),(300-33600),(300- 56000),(0,1),(0,1),(300-33600).

Subparameters

mod A decimal number that specifies the preferred modulation (automode enabled) or the modulation to use in originating or answering a connection (automode disabled). See the table on the next page.

automode An optional numeric value that enables or disables automatic modulation negotiation using V.8 bis/V.8 or V.32 bis Annex A. The options are:

0 = Disable automode

1 = Enable automode (default)

min_RX_rate An optional number that specifies the lowest rate at which the modem may establish a receive connection. The value is decimal coded in units of bps, e.g., 2400 specifies the lowest rate to be 2400 bps. See “Possible rates” in the mod table. The default is 300 for 300 bps.

max_RX_rate An optional number that specifies the highest rate at which the modem may establish a receive connection. The value is decimal coded in units of bps, e.g., 28800 specifies the highest rate to be 28800 bps. See “Possible rates” in the mod table. The default is 56000, for 56000 bps.

Multi-Tech Systems, Inc.

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