SMS messages for alarms stop being sent after functioning for a period of time. The messages are stuck in the queue which can be seen in the SmsService's 'Queue Size' property. Messages in the queue are sent when the GSM modem is reset (power cycle). Problem will reoccur again after a period of operation.
I/A Series G3 Enterprise Network Server
The GSM modem appears not to be able to handle the messages being sent from the I/A Series G3 SmsService.
In the SmsService properties, increase the 'Inter Message Delay' time. In this particular case, the delay has been increased to 1 second.
The 'Inter Message Delay' is defined as:
The delay between each command send to the GSM modem. By default this is set to zero. However, some older GSM modems may require this to be increased if there are problems with communication.