EC21-A unexpectedly enters airplane mode (CFUN 4)

Technical Subjects Software General Function
1

After several hours of connectivity I have several cases of EC21-A modules suddenly entering CFUN 4 without explicitly running any AT commands. I have also noticed that some modules when powering on enter CFUN 4 instead of the expected CFUN 1. Executing AT+CFUN=1 when in CFUN 4 causes the module to establish connectivity successfully. Executing AT+CFUN=1,1 when in CFUN 4 causes the module to reset, but enter CFUN 4 instead of the expected CFUN 1 state. Is there default radio power state configuration that I’m missing somewhere?

Behavior is seen on both of the following firmware versions:
EC21AFAR75A07M4G_30.002.30.002
EC21AFAR75A07M4G_30.001.30.001

2

I figured it may be useful to show the AT command output of one of the modules in question:

ATI?
EC21AFAR75A07M4G_30.001.30.001

OK
AT+CFUN?
+CFUN: 4

OK
AT+CFUN=1,1
OK

RDY

+CFUN: 4

+CPIN: READY

+QUSIM: 1

+QIND: SMS DONE

+QIND: PB DONE
AT+CFUN?
+CFUN: 4

OK
AT+CFUN=1
OK

+QIND: SMS DONE
AT+COPS?
+COPS: 0,0,"Mobile",7

OK
AT+CFUN=1,1
OK

RDY

+CFUN: 4

+CPIN: READY

+QUSIM: 1

+QIND: SMS DONE

+QIND: PB DONE
AT+CFUN?
+CFUN: 4

OK
3

Could you please check

at+qnvfr="nv/item_files/Thin_UI/enable_thin_ui_cfg"

Does it always enter CFUN 4 mode?

4

Yes, I can repeatedly cause the modem to enter CFUN 4 when restarting (AT+CFUN=1,1). The modem will enter CFUN 1 if setting it when in CFUN 4 state (AT+CFUN=1) but after several hours I find that it has entered CFUN 4 again. On modems with this issue I find the following is true:

at+qnvfr="nv/item_files/Thin_UI/enable_thin_ui_cfg"
+QNVFR: 00

OK

On modems I’m not having an issue with I find the following:

at+qnvfr="nv/item_files/Thin_UI/enable_thin_ui_cfg"
+QNVFR: 01

OK

I’m struggling to find documentation on this configuration, what does the Thin UI do?

5

So that you can set the modem with

at+qnvfw="nv/item_files/Thin_UI/enable_thin_ui_cfg",01

6

Thanks, I was able to update the value using that command. AT+CFUN=1,1 causes the modem to restart and return to the correct CFUN 1 state. I’ll begin more widespread testing this afternoon.

Is there any documentation you can send my way on this setting and what its purpose is? I’m unsure why the value was set on some of my modems and I’d like to ensure it doesn’t effect anything else.

7

For unknown reason, the nv was set to 0.
01 means mode is online.
Please do not set it everytime.

8

Thanks, things seem to be working during extended testing which is good.

What exactly is thin_ui_cfg? Is there any documentation I can read on what purpose it serves, I’m less concerned why it was set and more with what it actually does, I can’t find it in my EC21 AT commands documentation.