Specifications
SIM900 AT Command Manual       
SIM900_AT Command Manual_V1.03  141  12/24/2010 
See Write Command 
Response 
+CSDT: <mode> 
OK 
Read Command 
AT+CSDT? 
Parameter 
See Write Command 
Response 
OK 
ERROR 
Write Command 
AT+CSDT=<mo
de> 
Parameter 
<mode> 
0 switch off detecting SIM card 
1 switch on detecting SIM card 
Reference Note 
It is not supported temporarily. 
6.2.30 AT+CMGDA Delete All SMS 
AT+CMGDA Delete All SMS 
Response: 
+CMGDA: (list of supported <type>s) 
OK 
+CMS ERROR: <err> 
Test Command 
AT+CMGDA=? 
Parameter 
See Write Command 
Response: 
OK 
ERROR 
+CMS ERROR: <err> 
Write Command 
AT+CMGDA=<t
ype> 
Parameter 
<type> 
1) If text mode: 
 "DEL READ" delete all read messages 
 "DEL UNREAD" delete all unread messages 
 "DEL SENT" delete all sent SMS 
 "DEL UNSENT" delete all unsent SMS 
 "DEL INBOX" delete all received SMS 
 "DEL ALL" delete all SMS 
2) If PDU mode: 
   1 delete all read messages 










