Specifications
SIM900 AT Command Manual       
SIM900_AT Command Manual_V1.03  87  12/24/2010 
Reference 
GSM 07.07 [13] 
Note 
z  Minimum functionality mode(AT+CFUN=0)and RF disabled 
functionality mode (AT+CFUN=4) cannot be switched to each other.
z  The <fun> power level will be written to flash except minimum 
functionality. 
z  AT+CFUN=1,1 can be used to reset module purposely. Response 
string "OK" will be returned after module resets if baud rate is set to 
fixed baud rate. 
3.2.47 AT+CCLK Clock 
AT+CCLK Clock 
Test Command 
AT+CCLK=? 
Response 
OK
Response 
+CCLK: <time> 
OK 
If error is related to ME functionality: 
+CME ERROR: <err> 
Read Command 
AT+CCLK? 
Parameter 
See Write Command 
Response 
OK 
If error is related to ME functionality: 
+CME ERROR: <err> 
Write Command 
AT+CCLK=<tim
e> 
Parameter 
<time> string type(string should be included in quotation marks) 
value; format is "yy/MM/dd,hh:mm:ss±zz", where characters 
indicate year (two last digits),month, day, hour, minutes, 
seconds and time zone (indicates the difference, expressed in 
quarters of an hour, between the local time and GMT; range 
-47...+48). E.g. 6th of May 1994, 22:10:00 GMT+2 hours 
equals to "94/05/06,22:10:00+08" 
Reference 
GSM 07.07 [13] 
Note 
3.2.48 AT+CSIM Generic SIM Access 
AT+CSIM Generic SIM Access 










