Multi-Tech Systems GPRS (MTMMC-G) User Manual

Chapter 9 – Short Messages Commands  

Multi-Tech Systems, Inc. Wireless GSM/GPRS AT Commands (Document Number S000293I) 

76 

 

 

Description: 

The +CMGW command specifies a location in the SMS or Flash memory for the next SMS to be stored 
when the +CMGW indicates a message is ready to be stored. The defined location is used only once:  
+WMGO has to used again to perform another overwrite.  

• 

If the external application specifies a free location and an incoming message is received before the 

AT+CMGW command occurs, the product may store the incoming message at the specified available 
location. If the user then issues an AT+CMGW command without changing the location with another 
AT+WMGO, the received message will be overwritten. 

• 

The location number is not kept over a software reset. 

<loc>   Location number of the SIM record to write or overwrite. The number depends on the SIM or 

Flash memory capacity.

Syntax:   

Command Syntx: AT+WMGO= <loc> 

AT+CPMS? 
Note: Check the storage area 

+CPMS: “SM”,3,10,”SM”,3,10,”SM”,3,10 

AT+CMGW=”+33146290800”<CR> 
Hello how are you?

<ctrl-Z> 

+CMGW: 4 
OK 
Note: Message stored in index 4 in the SIM 

AT+WMGO=? +WMGO: 

(1-10) 

OK 
Note: Possible values for the SIM 

AT+WMGO=4 

AT+CMGW=”+33146299704”<CR> 
You are overwritten

<ctrl-Z> 

 

+CMGW: 4  
OK 
Note: New Message stored in index 4 

AT+WMGO? +WMGO: 

4 

OK 
Note: The value was used, so re-initialization 

AT+WMGO=4 OK 
AT+CPMS=”SM”,”ME,””SM” 

+CPMS: 3,10,0,99,3,10 
OK 
Note: Change the storage area from SIM to Flash 

AT+WMGO? +WMGO: 

(1-99) 

OK 
Note: Possible values for Flash 

AT+WMGO? +WMGO: 

0 

OK 
Note: We changed the storage area, so the value 
was reinitialized 

AT+WMGO=999 

+CMS ERROR: 321 

Note:  If the storage area is changed with the AT+CPMS command, the value of WMGO will be reset to 

zero.