Question regarding connection and Fallback

[Giannis Anastasopoulos]

Dear All,

In my application I need to switch on and off the modem using AT+CFUN=0 and AT+CFUN=4 respectivelly.

My question is the following. Let's assume that the device cannot find the preferred type of network and uses the fallback one. Then the modem is switched off. What will happen once the modem is back on again?

Will it try first to connect to the preffered network and then try the fallback, or will it try to connect to the previously working network first?

Thank you very much for your response

[Martin Lesund]

Hi Giannis,

Please make sure that you are using the correct functional modes in your question for the +CFUN command.

0 – Power off                  [Sets the device to minimum functionality. Disables both transmit and receive RF circuits and deactivates LTE and GNSS services.]
1 – Normal mode            [Sets the device to full functionality.]
4 – Offline mode             [Sets the device to "airplane mode". Disables both transmit and receive RF circuits and deactivates LTE and GNSS services.]
20 – Deactivate LTE       [Deactivates LTE without shutting down GNSS services]
21 – Activate LTE           [Activates LTE without GNSS]
30 – Deactivate GNSS    [Deactivates GNSS without shutting down LTE services]
31 – Activate GNSS        [Activates GNSS without LTE]
44 – Offline mode without shutting down UICC [Sets the device to airplane mode without shutting down UICC]

---

I assume that you mean AT+CFUN=1 and AT+CFUN=4 in your question:
I am pretty sure it will choose the last known working network e.g. the fallback in your case and try to connect to that one once you turn ON the modem again.
but let me double-check that functionality internally and come back to you.

Best regards,
Martin L.

[Giannis Anastasopoulos]

Dear Martin,

Yes, you are right. I meant AT+CFUN=1.

Please let me know of the results of your check