Specifications

SIM900 AT Commands Set
SIM900_ATC_V1.01 142 23.06.2010
Response:
+CBTE: < voltage>
OK
Read Command
AT+CBTE ?
Parameters
< voltage > battery voltage(mV)
Reference Note
z Only supported in SIM900D
z The temperature can be calculated according to the resistance of NTC
and the voltage supported by this command.
6.2.28 AT+CSDT Switch On or Off Detecting SIM Card
AT+CSDT Switch On or Off Detecting SIM Card
Response
+CSDT: <mode>
OK
Read Command
AT+CSDT?
Parameter
Response
+CSDT: (0-1)
OK
Test Command
AT+CSDT =?
Parameter
See Write Command.
Response
OK
ERROR
Write Command
AT+CSDT=<mo
de>
Parameter
<mode>
0 – switch off detecting SIM card (default)
1 – switch on detecting SIM card
Reference Note
It is not supported temporarily.
6.2.29 AT+CMGDA Delete All SMS
AT+CMGDA Delete All SMS