EC21 - Get preferred operator list with CPOL

Hi everyone,

for my project I’m using the EC21-E (Revision EC21EFAR02A09M4G) and I want to read the preferred operator list stored on the SIM Card.

Unfortunately “AT+CPOL?” gives me “+CME ERROR: operation not allowed” in response permanently.

I used the operator list on the SIM with another modem before, so it is stored and accessible.
I wonder if i missed some requirements for the EC21 before executing AT+CPOL?.

Has anyone had this kind of issue and can tell my why it fails?

Dear customer,

Generally, this error would be happened network registration is still onging or dennied. You would need t check AT+CGREG? or AT+CEREG? before perform this command.

Thank you for your hint @WillieYao.
As you suggested i double-checked the AT+CGREG and AT+CEREG Status and can confirm that the network registration is successfully done before the AT+CPOL error condition.

I tested another SIM today and the modem successfully read the preferred operator list from it.

It turned out, that the SIM-list with the described CPOL-error is missing the optional parameters ,<GSM_compact>, and .

As it seems to be a SIM related issue I will contact the provider and ask about the intention of having different types of preferred operator lists stored.

Thanks to all of you