There are 2 ways to check the NMEA coming into the d10
You can check for the arrival of recognised NMEA sentences by connecting to the d10 WiFi, opening a browser and entering the following URI:
Monitoring the TCP output
Using a terminal application like TeraTerm or a phone APP live TCP Client connect to port 10002 at ip address 192.168.20.1
You will see a stream of NMEA sentences from the internal GPS, heading and boatspeed plus any NMEA0183 or AIS data received by the wired connections.