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When cellular modem interface is enabled, System LED have have alternate indications:

blinking - connection establishment in progress, modem registered in cellular network, APN is not activated yetred  - SIM card not inserted

yellow  - established connection in 3G mode

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violet - established connection in 5G SA mode

blinking red  - SIM card not inserted- connection establishment in progress, modem registered in cellular network, APN is not activated yet

SIM slot usage

SIM card slot is designed to use with Micro SIM cards.
Nano SIM cards have different thicknesses, usage with an adapter is not recommended.

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