We continue to have issues with the SIMs that are preventing trial deployment and providing significant frustration. We activated a new SIM to place into our product, but what we are seeing are intermediate connectivity issues. With the new SIM, output of the AT+CSQ command repeated every second will return 99,99 for a long period of time and then 29,99 for just a few seconds before returning to 99,99. We are unable to establish a connection and the output of the AT+CEREG is not showing that we have registered.
In contrast the older registered SIM placed in the same hardware always shows the signal strength of 29,99 and can connect immediately.
Before suggesting to use a cellphone, the whole point of our current exercise is to be able to have our devices register automatically as soon as they have power. Suggestions would be appreciated as would explanation of what we should be seeing with a SIM when placed into the device.