Non-persistent FPLMN

Question

I'm trying to set the Forbidden PLMN list on a SIM using an nRF9160 and it all works until I power the SIM off and on again, whereupon the list is empty. 
 
 Here's an example using the "at_client" example app on an nRF9160 DK with an O2 SIM inserted, and the nRF Connect Serial Terminal on the PC: 
 
 > at+cfun=1 OK > AT+CRSM=176,28539,0,0,12 +CRSM: 144,0,"FFFFFFFFFFFFFFFFFFFFFFFF" OK > AT+CRSM=214,28539,0,0,12,"32F40132F451FFFFFFFFFFFF" +CRSM: 144,0,"" OK > AT+CRSM=176,28539,0,0,12 +CRSM: 144,0,"32F40132F451FFFFFFFFFFFF" OK > at+cfun=0 OK > at+cfun=1 OK > AT+CRSM=176,28539,0,0,12 +CRSM: 144,0,"FFFFFFFFFFFFFFFFFFFFFFFF" OK 
 
 What am I doing wrong? I'd like the forbidden list to be remembered over a SIM power-cycle (which I'm sure it should). 
 
 Thanks for any assistance! 
 
 Jonathan

Hakon · Accepted Answer

Alex Rawstorne said: What is the preferred method or retaining a persistent PLMN list which is SIM agnostic? 
 I'm not sure there is a good way for this. When the modem wakes up from PSM it should try to connect to the same network, so then you shouldn't need to worry about connecting to some other undesired network. But if you want to keep the FPLMN list in the modem at all times regardless of SIM then rewriting it to the modem seems like the best solution.

JonathanG · Answer

Thanks Hakon. I agree and so that's my next plan. 
 I'll check the PLMN after connection with AT%XMONITOR against our list of forbidden PLMNs and if it matches, disconnect, update the FPLMN list on the SIM and connect again.

Non-persistent FPLMN

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