Specifications

Chapter 4 – Serial Interface Control Commands
Multi-Tech Systems, Inc. AT Commands for EDGE (E1) Modems (S000474A) 70
4.9 AT+IPR Bit Rate (was called Set Fixed Local Rate)
Description: The command AT+IPR can be used to set and query the bit rate of the device's asynchronous
serial interface (UART).
The test command returns the values of the supported automatically detectable bit rates and the
values of the supported fixed bit rates.
The read command returns the current bit rate of the interface.
The write command specifies the bit rate to be used for the interface. The delivery bit rate value
(<rate>) is 115200bps. This setting will not be restored with AT&F.
If using a fixed bit rate, make sure that both the device and TA (termininal adapter) are
configured to the same rate. A selected fixed bit rate takes effect after the write command returns
OK and is stored in non-volatile memory. It is not recommended to set bit rates lower than 9600
bps in order to avoid timing problems (see Section 1.5, Communication between Customer
Application and the Device for details about timing).
In case of autobauding mode (AT+IPR=0) the detected TA bit rate will not be saved and,
therefore, needs to be resynchronized after any restart of the ME (for details refer Section 4.9.1,
Autobauding). If autobauding is activated, the TA will automatically recognize bit rate, character
framing and parity format (refer AT+ICF) currently used by the TE.
Syntax: Test Command: AT+IPR=?
Response: +IPR: (list of supported auto-detectable <rate>s) , (list of supported fixed-only
<rate>s)
OK
Read Command: AT+IPR?
Response: +IPR: <rate>
OK
Write Command: AT+IPR=<rate>
Response: OK
ERROR
+CME ERROR: <err>
Parameters:
<rate> <rate> will be displayed with AT&V.
bit rate per second (bps)
0 Activates autobauding. See Section 4.91, Autobauding for further details.
300
600
1200
2400
4800
9600
14400
19200
28800
38400
57600
115200
230400
460800
921600
Notes:
• Generally, AT+IPR should be used as a standalone command as specified in Section 1.4.2,.Concatenating AT
Commands.
∗ Avoid combinations with the AT commands listed in Section 1.4.2, Concatenating AT Commands.
∗ Take into account that there shall be a minimum pause between two AT commands as specified in
Section 1.5, Communication between Customer Application and the Device.
∗ If local echo is active (ATE1) and AT+IPR=x is entered with other commands you may encounter the
following problem: if switching to the new bit rate takes effect while a response is being transmitted, the
last bytes may be sent with the new bit rate and thus, not properly transmitted. The following commands
will be correctly sent at the new bit rate.
• T
his command is not PIN protected.
• This command is supported in airplane mode.