M95 AT+CREG? command returns +CREG: 0,2

IoT Modules GSM Module
1

Hi

I changed SIM-card and operator for my M95 based IoT device.
It all worked fine using the previous operator.

But now it fails during registering to the network

I get this error when calling AT+CREG?
+CREG: 0,2

The SIM-card can register to the network when inserting it into my phone

any ideas what could be wrong or what I should check?

br.
Allan

2

Dear Alkrojen,
Thanks for your inquiry in Quectel forum.
Please check the following information, you can use the following command to check the module status, then judge where is the problem? Thanks!
ATI
AT+CFUN?
AT+CPIN?
AT+CIMI
AT+CREG?
AT+CGREG?
AT+CSQ
AT+COPS?

3

Dear Kyson

Thanks for your answer.
I also asked the network operator we use, Greentel.
They recommended inserting the SIM-card into my phone, forcing it to use only the 2G/GPRS network, and make a phone call. After that I inserted it into our IoT equipment again, and now it works.
So problem is solved but the question is now why?

The SIM-card supports both 4G,3G and 2G. But M95 only supports 2G so I assumed it were forced to use 2G by default. So is there anyway I can avoid inserting the SIM-card in phone before use? by sending some commands to the M95?

br.
Allan

4

Dear Alkrojen,
Glad to hear that you have solve the issue. For this phenomenon, i think you can ask the SIM card supplier or the operator. As you know that the module M95 just can support 2G, but the SIM card can support both 4G,3G and 2G, so when you force it to register on 2G network on your phone, it can save the registration information(priori frequency) to the SIM card profile, when you insert it to module again, it will search priori frequency with highest priority, so it can register on 2G network easily. For M95 module, it have no command can fix it, the only way that you can do is waiting for longer time when you use the SIM card in the first time. Then next time it will register on network fast. Thanks!

5

Hi Kyson
Thanks. I extended the registering timeout to 3 minutes, and now all new SIM-cards registers to the network.
br.
Allan

6

It is really a good news. Please go on your test. Thanks!