I had power issues with my Quectel EC200U and while resolving them I noticed this problem, which I thought might’ve been power related, however apparently it is not, since I fixed these power problems and stabilized the module.
Sometimes the module can register on the network, but after SIM change and module restart, or even just module restart, it loses ability to register on the network or even scan for available networks.
ATI
Quectel
EC200U
Revision: EC200UEUAAR03A20M08
OK
AT+CFUN?
+CFUN: 1
OK
AT+CPIN?
+CPIN: READY
OK
AT+COPS?
+COPS: 0
OK
AT+CEREG?
+CEREG: 0,0
OK
AT+CREG?
+CREG: 0,0
OK
AT+QCFG="nwscanmode"
+QCFG: "nwscanmode",0
OK
AT+COPS=?
(long waiting)
CME ERROR: 3
I tried to reboot module using AT+CFUN=1,1, tried AT&F, AT+COPS=2, playing with AT+QCFG=“nwscanmode” and whatnot else.
I think physically powering the device off and on helps sometimes, but not sure, and this is undesired for obvious reasons. Signal quality in the location is maybe not the best, but AT+CSQ returns results from 11 to 16 and when the module works properly, there’s plenty of networks in sight.
Sometimes it just works with the same SIM and in the very same environment, connected to the same host device.
Various SIMs were tried.
What can cause this behaviour?
Is my current firmware fresh, can it cause this issue and if it is not fresh, can I get latest stable firmware for my module, or any other advise?