Specifications
SIM900 AT Command Manual       
SIM900_AT Command Manual_V1.03  149  12/24/2010 
Response 
MULTISLOT CLASS: (4,8,9,10)  
OK 
Test Command 
AT+CGMSCLA
SS=? 
Parameter 
See Write Command 
Response 
MULTISLOT CLASS: <class>  
OK 
Read Command 
AT+CGMSCLA
SS? 
Parameter 
See Write Command 
Response 
OK 
If error is related to ME functionality: 
+CME ERROR: <err> 
Write Command 
AT+CGMSCLA
SS=<class> 
Parameter 
<class> GPRS multi-slot class 
Reference 
Note 
6.2.43 AT+CDEVICE View Current Flash Device Type 
AT+CDEVICE View Current Flash Device Type 
Read Command 
AT+CDEVICE? 
Response 
Device Name: (Current flash device type) 
OK 
Reference 
V.25ter 
Note 
6.2.44 AT+CCALR Call Ready Query
AT+CCALR Call Ready Query 
Response 
+CCALR: (list of supported <mode>s)  
OK 
Test Command 
AT+CCALR=? 
Parameter 
<mode> a numeric parameter which indicates whether the module is 










