I am working with A7670G modules to replace SIM800L in agriculture projects. My question is, testing the A7670G, everything operates perfectly on startup for random short time periods(1hr, 3hr, 10 hr), then suddenly when an event occurs the A7670G does not (respond) read SMS or send SMS with a given input from MCU. The direct serial output from module preceding this failure includes:
+CGEV: NW PDN DEACT 1
+CGEV: NW REATTACH
+IMSUEEVENT: 0,7
+CGEV: EPS PDN ACT 1
+CGEV: NW PDN DEACT 1
+CGEV: NW REATTACH
+IMSUEEVENT: 0,7
+CGEV: EPS PDN ACT 1
Setting idle overnight, there may be 3-5 of these sets of items:
+CGEV: EPS PDN ACT 1
+CGEV: NW PDN DEACT 1
+CGEV: NW REATTACH
+IMSUEEVENT: 0,7
Then, sending an SMS to the A7670G may take 20 minutes to get a response.
The registration status is: +COPS: 0,2,"310260",7. Signal strength is very good. The flashing network indicator never stops and the module always responds to AT commands. The previous SIM800L modules I used were very reliable and just worked. What could be causing this behavior?
Any advice greatly appreciated.