Would it be possible to have some test facilities for the GSM module in Configurator/firmware in the future.
Maybe a button to do a test dial out. Maybe show if you have network connectivity. Maybe show minutes left. Or some stats, last dialout & last incoming request date etc.
I originally had a Vodafone PAYG sim in mine not realising that if it's not used for 90 days then it automatically disables. Only indication I had of potential issue was a flashing keypad LED and UCM trouble message. I had to remove sim on put in phone to see what was happening; that would mean opening up the Comfort Chassis etc. Also being able to heathcheck remotely via software is better.
I've switched to contract now but maybe some features to help here. Maybe it's just setup; ie if I'd sent an sms each day on say the battery check then it would have been enough of a keep-alive.
It may be useful to know what the balance in the SIM card is, but the UCM/GSM is not able to read that information.
Typically the provider sends a SMS textmesage so you have to read it, but that information is not avialable from the SIM card or the network