Below is the connection diagram diagram for the iEFIS-Lite to V10 Com Radio. You can use either RS-232 Port 1 OR RS-232 Port 2 on the iEFIS-Lite (Discovery-Lite, Explorer-Lite, Challenger-Lite)
Connect either RS-232 on the iEFIS-Lite to RS-232 Port 1 on the Radio.
Remember that RX on the Lite goes to TX on the Radio and TX on the Lite goes to RX on the Radio