Hi
I am having issues with SIM cards on Data modems.
We use data modems to send and recieve SMS messages for remote monitoring and control.
I have found that in same cases, Prepay cards work fine until we do a top up and then we can not recievew SMS on the modem. The SIM cards do however work fine in a phone.
I recently had a case where a new prepay will not work on a 3G site but an on account SIM card will.
There are obviously some differences, but not sure what they are. I expect that we can overcome by initialisation settings on the modem if I knew what the doifferences were.
Any thoughts?
Best regards,
Mark.