Modulation Control Commands; Ms - Modulation Selection - AOpen FM56 Manual

3.2.4 Modulation Control Commands

3.2.4.1 +MS - Modulation Selection

This extended-format compound parameter controls the manner of operation of the
modulation capabilities in the modem. It accepts six subparameters:
Syntax
+MS=[<carrier>[,<automode>[,<min_tx_rate>[,<max_tx_rate>[,<min_rx_rate>[,<max_rx_
rate>]]]]]]
Defined Values
<carrier> A string which specifies the preferred modem carrier to use in originating or
answering a
connection. <carrier> values are strings of up to eight characters, consisting only of
numeric digits
and upper case letters. <carrier> values for ITU standard modulations take the form:
<letter><1-4
digits><other letters as needed>. Defined values are:
B103 For Bell 103
B212 For Bell 212
V21 For V.21
V22 For V.22
V22B For V.22bis
V23C For V.23
V32 For V.32
V32B For V.32bis
V34 For V.34
K56FLEX For K56flex
The modem may also automatically switch to another modulation (automode), subject to
several
constraints:
1. The modem may not support some other modulations, regardless of the automode
mechanism supported.
2. The modem may not be able to automatically switch from the current modulation
<carrier> to some other modulations, restricted by the selected modulation standard and
by the modem manufacturer's technology. For example, there is no standard way to
automode from V.32bis to V.27ter.
3. The DTE may disable automode operation, see <automode> below.
4. The DTE may constrain the range of modulations available, see <min_rate> and
<max_rate> below.
5. The DTE may selectively disable some modulations by reading, editing and writing the
+MA parameter (6.4.2).
If the DTE issues a +MS=<carrier> command to the modem, and if the modem supports
the +MA
parameter, the modem will reinitialize the +MA parameter.
<automode> An optional numeric value which enables or disables automatic modulation
negotiation (e.g., ITU-T V.32 bis Annex A or V.8). The default value is enabled if it is
defined for the associated
modulation (e.g., ITU-T V.32 bis, V.8 for V.34); however, there are modulations for which
there is
no automatic negotiation defined (e.g., V.26 bis).
0 = Automode disabled.
1 = Automode enabled, with V.8 or V.32bis Annex where applicable. (Default.)
For <automode> = 0 (automode disabled, i.e., fixed modulation):