Switch to UPLMN List

IoT Modules LTE Standard Module
1

Hi, we are using a few hundred devices with an builtin EG25G and would like to edit the User defined PLMN list.
AT+CPOL? lists only the operator defined list and can’t be edited.
In the AT Commands Manual is no AT+CPLS command listed and when setting AT+CPLS=0 there is no effect.

Is there any way to set the UPLMN List with this module?
I also noticed, that CMEE does not have any effect on the error message.
When Trying to set a entry with CPOL just returns ERROR. I guess because I can’t edit the Operator list.

Thanks for your help.

ATI
Quecel
EG25
Revision: EG25GGBR07A07M2G

2

Is this the User controlled PLMN selector with Access Technology at SIM address 0x6F60?

You can read it with: AT+CRSM=176,28512,0,0,0

I expect you can overwrite it with AT+CRSM=214,28512... (supplying the desired arguments).

3

thanks for your help.

this works.
Sadly it is not persistent across reboots. Am I missing something or is this SIM specific.
Otherwise I just can apply my list after every reboot as a workaround.

4

I’m dumbfounded to say the least. My tests confirm your findings.

After a hard modem reset (AT+QPOWD=0), the SIM contents have reverted.

This is quite unlike the changes I make to the Forbidden PLMNs file at SIM address 0x6F7B. These stick.

I can find no reason for the lack of permanence mentioned in 3GPP 31.102.

5

An update:

I’ve tried the +CRSM command to change the contents of file 0x6F60 using a different modem (Fibocom L860-GL) and with a different SIM.

The change survived a modem power-cycle.

Thinking the temporary nature on my Queclel RM500Q-AE might be caused by MBN, I disabled that and tried again.

The SIM in the Quectel still reverted to the previous setting.

6

Update 2:

The problem follows the SIM and not the modem.

7

thanks for sharing your findings. Seems like I have to implement the workaround. The current solutions should be sufficient for now.