Chapter 2 – AT Commands
Multi-Tech Systems, Inc. AT Commands Reference Guide (S000273G) 24
Command: +IPR Fixed DTE Rate
Description: This numeric extended-format parameter specifies the data rate at which the modem will
accept commands during online operation. It may be used to select operation at rates at
which the modem is not capable of automatically detecting the data rate being used by the
DTE.
Specifying a value of 0 disables the function and allows operation only at rates
automatically detectable by the modem. The specified rate takes effect following any
issued result code(s) associated with the current command line.
The <rate> specified does not apply in OnLine Data State if Normal Mode (Direct Mode) of
operation is selected.
Syntax: +IPR=<rate>
Values: <rate> Specifies the DTE-modem interface operation rate in bits/s. The available rates
are: 0, 300, 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200, or 230400.
If unspecified or set to 0, automatic detection is selected and the character format is also
forced to auto detect. +ICF=0.
If the specified rate is not supported by the modem, an ERROR result will be returned.
Report Commands: +IPR? Reports current or selected values.
+IPR=? Reports supported range of parameter values.
Command: +MR Modulation Reporting Control
Description: This extended-format numeric parameter controls whether or not the extended-format
+MCR:<carrier> and +MRR:<rate> intermediate result codes are transmitted from the
modem to the DTE. If enabled, +MCR:<carrier> and +MRR:<rate> intermediate result
codes represent the current (negotiated or renegotiated) modulation <carrier> and <rate>
that are transmitted at the point during connect negotiation (handshaking) at which the
modem has determined which modulation and rate will be used; i.e., before any Error
Control or Data Compression reports are transmitted and before any final result code
(e.g., CONNECT) is transmitted.
S95 bit 2 is reset to 0 for +MR=0 and is set to a 1 for +MR=1 or +MR=2. The more recent
setting of +MR or S95 bit 2 and the W command setting determines modulation result
code reporting (see S95 Parameter and W Command).
Syntax: +MR=[<value>]
Values: <value> A decimal number corresponding to the selected option:
0 Disables reporting of modulation connection (+MCR: and +MRR: are not
transmitted). Default
1 Enables reporting of modulation connection (+MCR: and +MRR: are
transmitted with tx rate, rx rate).
2 Enables reporting of modulation connection (+MCR: and +MRR: are
transmitted with rx rate only).
Report Commands: +MR? Reports current or selected values.
+MR=? Reports supported range of parameter values.
+MCR: Report Syntax: Response: +MCR: <carrier>
<carrier> Alphanumeric code corresponding to the reported carrier.
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
V90 for V.90
V92 for V.92
+MRR: Report Syntax: Response: +MRR: <tx_rate>,<rx_rate>
<tx_rate> Decimal transmit rate in bits/s.
<rx_rate> Decimal receive rate in bits/s.