Specifications

Chapter 4 – Serial Interface Control Commands
Multi-Tech Systems, Inc. AT Commands for EDGE Modems (S000371B) 53
• For compatibility reasons, the command can be used in Multiplex mode, though the settings will not take
effect. Please note that changes made on multiplex channel 1 will be saved with AT&W and will become active
when restarting the ME after AT^SMSO.
• To start the multiplexer it is necessary to set the character framing to 8 bits, no parity and 1 stop bit.
• If a <format> is selected without parity (e.g. <format>=3) and you try to activate a format with parity (e.g.,
<format>=2), you need to explixitly set the parameter <parity> (e.g. AT+ICF=2,1). Otherwise you will get
‘+CME ERROR: invalid index’. This is because for <format>=3, the parameter <parity> is set to the internal
value ‘no parity’ which is not supported by <format>=2. (Remember that if an optional parameter is omitted for
which no default is stated in this specification, the value of the parameter remains unchanged).
4.7 AT+IFC Set Flow Control Separately for Data
Directions
Description: The command AT+IFC can be used to set or query the data flow control separately for
each data direction. In contrast to this, flow control settings made with AT\Q are valid in
both data directions.
Test Command Syntax: AT+IFC=?
Response(s): +IFC: (list of supported <TEflowcontrol>s), (list of supported <TAflowcontrol>s)
OK
Read Command Syntax: AT+IFC?
Response(s): +IFC: <TEflowcontrol>, <TAflowcontrol>
OK
Write Command Syntax: AT+IFC=<TEflowcontrol>, <TAflowcontrol>
Response(s): OK
ERROR
Parameter Descriptions:
<TEflowcontrol>
Specifies the method used by the TE when receiving data from the TA.
0 none
1 XON/XOFF, terminate flow control in the Cellular Engine
2 RTS line
3 XON/XOFF, evaluate flow control in the Cellular Engine and pass it through (over the air)
to the opposite TE
<TAflowcontrol>
Specifies the method used by the TA when receiving data from the TE.
0 none
1 XON/XOFF
2 CTS line
Notes:
• When using XON/XOFF flow control (AT+IFC=1,x or AT+IFC=3,x) in data mode, +++ should not be used while
the data transmission is paused with XOFF. Before entering the command mode with +++ the paused
transmission should be resumed using the XON character.
• For compatibility reasons, the AT+IFC command can be used in Multiplex mode, though the settings will not
take effect. However, be aware that whenever you use the AT+IFC write command in Multiplex mode and then
save the current configuration to the user profile with AT&W, the changed AT+IFC setting will become active
after restart.
4.8 AT+ILRR Set TE-TA Local Rate Reporting
Description: The command AT+ILRR controls whether or not the intermediate result code “+ILRR” is
transmitted from the TA to the TE while a connection is being set up. The result code indicates
the local rate. It is issued before the final result code of the connection; e.g., CONNECT is
transmitted to the TE.
Test Command Syntax: AT+ILRR=?
Response: +ILRR: (list of supported <value>s)
OK
Read Command Syntax: AT+ILRR?
Response: +ILRR: <value>
OK
Write Command Syntax: AT+ILRR=<value>
Response: OK
ERROR
+CME ERROR
Intermediate Result Code: +ILRR: <rate>
Indicates local port rate setting upon connection setup.