i´m experiencing a problem with at+cgatt=1 command. sometimes it doesnt return any value for about 2 minutes, during this time any AT command(exept at+cfun=1) returns error. After 2 minutes the responce is “+CME ERROR: 148”.
could anyone tell me where the problem is? i´ve checked the gprs parameters(CID, APN, user name, password) and they are correct.
thanks,
Your SIM does not have GPRS functionality enabled. In such a case, contact your service provider.
The received signal strength by the module is very weak. Hence, the module is not able to attach to the network. In such a case, you can execute AT+CSQ command to check the received signal strength.
Check to see, if the SIM you are using is in roaming. In such a case, the PLMN on whose cell it is camping might not be providing it with GPRS services.
The problem that the module gives you ERROR when you try to execute some other command when AT+CGATT=1 was previously issued is because, the module is busy performing the attach operation. Hence, it is not allowing you to enter another command.
If you have entered a command and it hasn’t finished executing you will receive an error on every new command you try to execute (as OpenAt_Fan wrote).
When modem/module is in this state, you can always abort the current executing command with the AT+WAC command ([color=blue]Wavecom [color=blue]Abort [color=blue]Command)