Wireless Joint

I'm using the following USB to M2 adapter: https://thewirelesshaven.com/shop/mini- ... dapter-v7/
for a Telit FN990 5G modem. Unfortunately I am keep getting SIM not detected. Tried directly sending AT comands as well as using ModemManager, but the results are the same.
Also tested with 3 different SIMs but the results are the same.

Any help is highly appreciated.
Regards,
Fabrizio

What is the specific response from AT+ICCID

Unfortunately I'm getting SIM failure:

AT+ICCID
+CME ERROR: SIM failure

I have tried to reverse the SIMIN polarity (AT#SIMINCFG) and after switching the SIM slot with AT#SIMDET, I'm getting something:
AT#SIMPR?
#SIMPR: 0,0,1
#SIMPR: 0,1,0

(slot #0 seems to have SIM detected), but any attempt to read any value off it, keep responding with error:
AT+CIMI
+CME ERROR: SIM not inserted

Regards,
Fab

Have you also been polling with: AT#SIMDET ?

The Telit modem stuff is not my strongest. I wish all these modem manufacturers would stop with the extremely different (read: "proprietary") methods to use the exact same things.

Have you tested the adapter with another modem brand/model to see if it reads the SIM?

Thank you so much for trying to help... I really appreciate. I feel at least I can speak with someone who knows more than me here (Telit support is not really helping)...

So, polling with AT#SIMDET? is the only way to get the modem to at least detect a change in the SIMIN pin...
To be more precise after a reboot (with SIM inserted), I query AT#SIMDET? few times, but no changes, then I switch between slot 0 to slot 1 and back to slot 1, and only at that point it reports SIM inserted (through a SIMPR unsolicited message)....
SIMDET? reports SIMIN pin high, and even a direct query through AT#SIMPR? reports present....
... but AT#SIMSS still says "no SIM"
... and even AT+CIMI reports "ERROR: SIM not inserted"

It seems the SIM card is detected (the SIMIN polarity seems need to be HIGH instead of the default LOW)... but there are communication issues with it...

I am trying to test it with a different adapter, but the adapter "recommended" (and supported) by Tecship/Telit is out of stock... I guess I can try with an older adapter this week but I have to remove some LED around the M2 connector (in the adapter) because this modem module won't fit.

Another thing I need to try is to upgrade the firmware of the module... will keep you posted.
Thanks again for your suggestions.

Keep us posted.

In my experience Telit has been a little weird with their implementations.