FMC920 Auto-Reconnection Issue - Firmware 03.29.00 Rev21

My situation:

I’m experiencing an issue with my FMC920 (firmware 03.29.00 Rev21) located in South America. The device works correctly in general, but shows problematic behavior:

Problem:

  • GPS sends data normally to my server

  • When passing through areas without cellular coverage, it disconnects (expected behavior)

  • The issue: When returning to areas with good coverage (city center where other GPS devices work fine), it does NOT automatically reconnect

  • These disconnections can last for days until it finally reconnects on its own

Analysis from .dmp file via FOTA Web: The error that constantly appears is related to SIM card initialization:

[AT.RSP]
SIM card is not initialized yet
[AT.SEND] 
ERROR @ m2m_at_cmd_api.c(298):CMD failed. Try:2
[AT.RSP]
SIM card is not inserted.
[MODEM]
Setting PWR state 1->0
[MODEM]
Changing Modem State from:1 to:2
[SCH]
Task eM2M_Tid_ModemInit[8] has been scheduled. Period: 5s

Additional details:

  • SIM card has not been physically removed

  • Device has internet access when working

  • GPS gets fix correctly (GPS Fix: 1, GPS state: 1)

  • Normal battery voltage (BatV: 4070, ExtV: 13654)

  • The issue seems to be specifically with modem/SIM reconnection

Has anyone experienced this behavior? Is there any specific configuration I should check to improve automatic reconnection after coverage loss?

Any suggestions would be greatly appreciated.

Thanks in advance.

hello @jose.1060

Good day!

there is a delay timer for the modem to refresh the operator queue and try to connect to a new operator code to get the service if the signal is available and there is no service,

this was enhanced in the new FW: https://wiki.teltonika-gps.com/view/Special:Redirect/file/FMB.Ver.04.00.00.Rev.14_and_configurator.zip

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