US Robotics 56K USB Modem User Manual page 55

Table 104. +MR Extended Syntax Commands
Command
+MR=<value>
+MR?
+MR=?
+MS=<carrier>,<automode>,<min_rate>,<max_rate>,<min_rx_rate>,
<max_rx_rate>—Modulation Selection
Use this command to set the modem's modulation, the modulation's minimum and maximum transmission
rates, and the status of automatic modulation negotiation (automode). The <carrier>, <min_rate>, and
<max_rate> parameters define the modulation and its minimum and maximum transmission rates.
<min_rx_rate> and <max_rx_rate> define the minimum and maximum reception rates. The minimum
transmission and reception rates are always set to 0.
The <automode> parameter enables or disables automatic modulation negotiation. If a subsequent +MA
command is not provided, the automode parameters are constrained by the modulation set by the
<carrier> parameter. The +MA command can further restrict the automatic modulation negotiation settings
but it cannot set a modulation that is higher than the modulation set by the +MS command.
Result codes:
• OK if <automode> = 0, 1 and <min_rate> = <min_rx_rate> = 0 and <max_rate> = 0, 300—33600 and
<max_rx_rate> = 0, 300—56000 and carrier is equal to one of the entries in Table 105.
ERROR if <automode> ≠ 0, 1 or <min_rate> ≠ <min_rx_rate> ≠ 0 or <max_rate> ≠ 0, 300—33600 or
•
<max_rx_rate> ≠ 0, 300—56000 or carrier is not equal to one of the entries in Table 105.
Table 105. Valid <carrier> Values
Value
V92 V.92 (default)
V90 V.90
V34 V.34
V32B V.32bis
V32 V.32
V22B V.22bis
V.22 V.22
Bell212A Bell 212A*
V23C V.23, constant carrier, asymmetric FDM
V21 V21
Bell103 Bell 103*
* The +MS command was standardized by ITU-T Recommendation V.250. However,
the standard command does not include the additional functionality provided by the
Bell212A and Bell103 values of the <carrier> parameter.
Automatic modulation negotiation is enabled or disabled by <automode>. However, if a value is specified
for the <max_rate>, automatic rate selection is disabled and the modem attempts to connect at the
specified rate.
Table 106. Valid <automode> Values
Value
0 Disabled.
1 Enabled (default).
Selects or deselects transmission of the modulation result codes.
Displays the current status of the modulation report result code.
Displays the supported parameter values for modulation rate reporting.
Meaning
Meaning
56K USB Modem
Description
Command Reference - 49
User Guide