User guide

Chapter 3 – Supported GSM/WCDMA AT Commands
High Speed HSPA-H4 AT Commands Reference Guide (Document S000483A) 53
+IPR Set Fixed DTE Rate
Description: This command specifies the data rate at which the data circuit equipment (DCE) will accept
commands.
Notes:
• The serial autobauding feature is supported for the following serial speeds only:
1200, 2400, 4800, 9600, 19200, 38400, 57600 115200, 230400, 460800, 921600 bps.
Beyond those serial speeds, proper operation of the modem is not guaranteed.
• Any AT command issued by the DTE must start with both capital ‘A’ and ‘T’ (or ‘/’) or
both lower case ‘a’ and ‘t’ (or ‘/’); otherwise, the DCE may return some garbage
characters and become desynchronized. Should this happen, the DTE simply issues
‘AT\r’ (at 2400 or 4800 bauds) once or twice or just ‘AT’ (at 9600 bauds) to
resynchronize the modem.
• The DTE waits for 1ms after receiving the last character of the AT response (which is
always ‘\n’ or 0x0A) to send a new AT command at either the same rate or a new rate.
Should this delay be ignored, the DCE can become desynchronized. Once again,
sending ’AT\r’ once or twice or just ‘AT’ causes the DCE to recover.
Caution: When starting up, if autobauding is enabled and no AT command has yet been
received, the product sends all unsolicited responses (like RING) at 9600 bauds.
Syntax:
Command Responses
Action Command:
AT+IPR=<rate>
OK
Read Command:
AT+IPR?
+IPR: <rate>
OK
Test Command:
AT+IPR=?
+IPR: (list of auto-detectable <rate>s), (list of supported <rate>s)
OK
Values: <rate> Baud Rates That Can Be Used by the Data Circuit Equipment (DCE).
0 Enables autobauding. Default
300
600
1200
2400
4800
9600
19200
38400
57600
115200
230400
460800
921600
Parameter Storage: The <rate> parameter is stored in EEPROM using AT&W. The default value can
be restored using AT&F.
Examples:
Command Responses
AT+IPR? +IPR: 9600
OK Note: Current rate is 9600 bps
AT+IPR=? +IPR:
1200,2400,4800,9600,19200,38400,57600,115200,230400,460800,
921600) , (0,300,600,1200,2400,4800,9600,19200,38400,57600,115200,
230400,460800,921600)
OK
Note: Possible values, according to V25 ter Recommendation:
The first set of values indicates the range of auto-detectable baud rates.
The second set of values indicates the baud rates supported by the DCE.
AT+IPR=38400 OK Note: Disable autobauding and set rate to 38400 bps
AT+IPR=0 OK Note: Enable autobauding