Skip to main content

Documentation Index

Fetch the complete documentation index at: https://docs.hologram.io/llms.txt

Use this file to discover all available pages before exploring further.

​
About the FPLMN list

The FPLMN (Forbidden Public Land Mobile Network) list is stored on the SIM and contains networks the device should avoid.
Caution: Only clear the FPLMN when instructed by Hologram support or your device vendor. Doing this at the wrong time can disrupt registration.

​
Check the FPLMN

AT+CRSM=176,28539,0,0,12
If the response shows 24 Fs, the list is empty: 
+CRSM: 144,0,"FFFFFFFFFFFFFFFFFFFFFFFF"
AT+CRSM read showing 24 Fs indicating empty FPLMN

​
Clear the FPLMN

Before writing, set minimal functionality if required by your module: 
AT+CFUN=0
Write exactly 24 Fs: 
AT+CRSM=214,28539,0,0,12,"FFFFFFFFFFFFFFFFFFFFFFFF"
Warning: Include exactly 24 Fs in the payload.
AT+CRSM write showing 24 Fs to clear FPLMN
Restore full functionality afterward: 
AT+CFUN=1