I’m puzzled about the behaviour of an application using Open AT that should be ludicrously simple. In order to keep a PAYG SIM card active my embedded application automatically makes calls to preprogrammed “voice” telephone numbers. The call is initiated in the normal manner using adl_CallSetup and there is no problem in making a connection and receiving all the events associated with making the call. However, when the remote connection is disconnected the embedded application receives no event at all. My handler for call-events, registered using adl_callSubscribe, receives nothing!
I have tried putting in a handler for the “NO CARRIER” unsolicited response, but again nothing is received.
After one minute my application times out and forces the line to be disconnected. The call-event handler receives all the usual responses from the modem.
To summarise: the call-event handler sees all the events associated with calling, ringing and connecting, but nothing for when the line is disconnected by the remote end.