This setting tells the instrument whether to use internal or external antenna(s).The instrument normally uses an internal antenna for the cellular modem.
In places where the GSM coverage is poor you could mount an external antenna to the Main antenna plug on the instrument and get better radio signals. Even better, you could mount two external antennas, one to the Main plug and one to the Sec plug, and get diversity functionality and even better radio signals.
Use this command if you have trouble with your NorCloud connection. This will tell you if you have access to the internet. The default address '8.8.8.8' (Google) should always be available.
If no connection, remember to disconnect both usb and net cable.