Chapter 1 – AT Commands, S-Registers, and Result Codes
Multi-Tech Systems, Inc. AT Commands for the MultiModem & SocketModem MT9234 Series (S000434H)
30
Reports
:
+IPR?
Reports current or selected options.
+IPR=?
Reports
supported
options.
Result Code:
OK
+ITF
Transmit Flow Control Threshold
Description:
Use this command to set the flow control thresholds. The <off> parameter represent
the off signal threshold in octets. When this threshold is reached the DCE generates
a flow off signal. The <on> parameter represents the on signal threshold in octets.
When the volume of data resident on the DCE goes below this value the DCE
generates a flow on signal.
Syntax: AT+ITF=<off>,<on>
Reports
:
+ITF?
Reports current or selected options.
+ITF=?
Reports
supported
options.
Result Code:
OK
ERROR
+MR
Modulation Reporting Control
Description:
Use this command to hide or display the modulation report. When the modulation
report is enabled, the DCE transmits the +MRR: <rate>, <rx_rate> and the
+MCR:<carrier> intermediate result codes to the DTE.
The <carrier> reported is the current modulation; for example, V.34.
The <rate> reported is the transmit rate in bits per second or is zero if negotiation
fails.
The <rx_rate> is the receive channel rate and is only reported when different receive
and transmit rates have negotiated.
The intermediate result codes are transmitted after the modulation and the rate have
been determined and before any error control or data compression reports or the final
result code (e.g., CONNECT) is transmitted.
Syntax: AT+MR=<value>
Values:
+MR=0 Turns off the modulation report.
+MR=1 Turns on the modulation report.
Reports
:
+MR?
Reports current or selected options.
+MR=?
Reports
supported
options.
Result Code:
OK
ERROR
+MS Modulation
Selection
Description:
Sets the modem’s modulation, the modulation 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.
Once a modulation is selected by the
+MS
command, the autorate in both directions
and the automode is activated unless <max_rate> is specified by in the command.
The settings of this command overwrite the settings of S28 and S37. Likewise,
changes to these registers overwrite the settings of the
+MS
command.
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