Rockwell RCV144ACx, Command Reference Manual, Page: 44 / 186

AT Command Reference Manual
3-26 1048
Subparameter Definitions
1. <mod> = A decimal number which specifies the preferred modulation (automode enabled) or the modulation (automode
disabled) to use in originating or answering a connection. The options are:
<mod> Modulation
Possible Rates (bps) 1
Notes
0
V.21 300
1
V.22 1200
2
V.22 bis 2400 or 1200
3
V.23 1200 See Note 2
9
V.32 9600 or 4800
10
V.32 bis 14400, 12000, 9600, 7200, or 4800 Default for RC144
11
V.34 33600, 31200, 28800, 26400, 24000, 21600,
19200, 16800, 14400, 12000, 9600, 7200, 4800, or
2400 Default for RC56/RC336/RC288
[RC56/RC336/RC288 only]
56
K56flex 56000, 54000, 52000, 50000, 48000, 46000,
44000, 42000, 40000, 38000, 36000, 34000, 32000 [RC56 only]
64
Bell 103 300
69
Bell 212 1200
Notes:
1. See optional <automode>, <min_rate>, and <max_rate> subparameters.
2. For V.23, originating modes transmit at 75 bps and receive at 1200 bps; answering modes transmit at 1200 bps
and receive at 75 bps. The rate is always specified as 1200 bps.
The modem may also automatically switch to another modulation (automode), subject to the following constraints:
a. The modem may not be able to automatically switch from the current modulation (specified by <mod>) to some
other modulation. For example, there is no standard way to automode from Bell 103 to V.23.
b. The DTE may disable automode operation (see <automode> below).
c. The DTE may constrain the range of modulations available by specifying the lowest and highest rates (see
<min_rate> and <max_rate> below).
2. <automode> is an optional numeric value which enables or disables automatic modulation negotiation using V.8 bis/V.8
or V.32 bis Annex A. The options are:
<automode> Option Selected Notes
0
Automode disabled
1
Automode enabled using V.8 bis/V.8 or V.32 Annex A Default
The default value is 1, which enables automode. Note, however, there are modulations for which there is no automatic
negotiation, e.g., Bell 212 (<mod> = 69).
For <automode> = 0 (automode disabled, i.e., fixed modulation):
a. If <max_rate> is within the rates supported by the selected modulation, the selected rate is that specified by
<max_rate>. For example:
+MS=10,0,1200,4800 selects V.32 bis 4800 bps fixed rate.
b. If <max_rate> is greater than the highest speed supported by the modulation specified by <mod>, the starting
rate is the highest rate supported by the selected modulation. For example:
+MS=10,0,2400,14400 selects V.32 bis 14400, 12000, 9600, 7200, or 4800 bps.