'CMS ERROR 515' is received in the following cases:
1. Sending a SMS when the SIM initialization is going on (after rebooting the module).
2. Reading a SMS immediately after booting the module when SIM initialization is not yet over.
3. Writing a SMS to the memory before SIM initialization is complete.
4. Sending more than one SMS at a time or sending a SMS when the response (OK or ERROR) for a previously sent SMS has not been received.
hay, i am using sim300 and i am also getting the same error. actually i am trying to send sms with gprs link. following is the command sequence i am following.
AT+AGATT=1
AT+CGSMS=0
after this i wait for a while and then send the sms sending command.
AT+CMGS="mob num"
>message then ctrl z
+CMS Error 515