i need to figure out why the NEMA com port no longer shows and how to fix this issue.
Please check that NMEA interface is configured on your module by AT command !USBCOMP as below:
AT!ENTERCND=<“key”> AT!USBCOMP? (Response should have "nmea" value)
You can refer below picture:
If NMEA interface is not configured on your module, you must enable it.
You can refer more information for AT command !USBCOMP at page 56 in this document: AirPrime EM74xx-MC74xx AT Command Reference
What would you use to connect to the sirerra wireless unit.
Which connection do you want? Is the connection to send AT command?
If yes, can you go to Device Manager > Modems and check whether AT port exists in menu? You can refer below picture:
If you cannot see AT port as above picture, please re-install Windows driver for your module. You can get this driver at link: https://source.sierrawireless.com/resources/airprime/software/airprime-em_mc-series-windows-drivers-qmi-build-latest-release/#sthash.43GdCH5t.dpbs