Normally, the procedure to activate the PDP context via AT-commands is with the ATD99# or ATD99***1#.
The tech support usually do not have any good information and its nothing else do to except to stay put in telephone queues for half an hour just to get a stupid answer on your question. But eventually there is a bright answer or a person that knows what he/she is talking about and then its recommended to write down that persons contact information for later use…
However, some network operators do have a specific M2M/Vertical market or another specialized tech support. They usually knows what they are talking about…
I have never heard of any dial code like 600 to activate GPRS context. All over the world (as far as I know) its only been 99# or 991#.
Yeah, but you need to be attached (AT+CGATT=1) to the GPRS network first (AT+CGREG? must give 1 or 5). And I suggest you to first test the module with the AT-command controlled TCP/IP stack and a terminal. Its easier and more clean and eliminates programming errors that could mess up things in an OAT embedded application.
Try to enable extended error result codes with AT+CMEE=1 and you will probably get an error code together with the error message. That could give you a clue of whats going wrong.
Some other things to check is of course the usual stuff:
-Do you really have GPRS enabled on your subscription (SIM card),
-Do the SIM work in a GPRS mobile phone?
-If answer is no the questions above: Check with your network operator
-Do you have enough signal strength in the area you are testing (check with AT+CSQ)
-Are you using the correct parameters APN/UN and PW?
-Are you really sure your module software supports the GPRS feature (it can be disabled… and in this case you need to contact your Wavecom distributor/contact)?
see also the thread: