GDL 82 Mooney M20( ) Series STC Installation Manual 190-01810-10Rev. 1Page 40 of 49To configure the GNS 480:1. Power on the GNS 480 unit.2. Push, in sequence, line select key 1, line select key 4, and the MENU/ENTER key to enterGround Maintenance mode.3. From the SETUP page, select SERIAL PORTS.4. Configure the Serial (RS-232) Port Channel 3 as specified in Table 5-2.NOTEThe GNS 480 Serial Port Channel 3 is the only port that provides the ADS-B OUT+ format for anexternal GPS source to the GDL 82.5.3 Ground Checks (Configuration Mode)Each installation of the GDL 82 must be checked by performing the following procedures:• GDL 82 System Faults• Internal GPS Receiver• External GPS Source• Transponder (ADS-B) Interface• Discrete Input and Output5.3.1 GDL 82 System FaultsDiagnostics / Faults and Diagnostics / ADS-B pages in the GDL 8X Install Tool can be used to checkthat the GDL 82 is receiving data from the interfacing system(s).Any annunciated failures on the Faults page should be corrected prior to proceeding with the groundchecks. The Configuration Fault will activate if the GDL 82 system configuration was not set properly.See Table 5-1 for proper GDL 82 configuration settings.Refer to the Instructions for Continued Airworthiness & Maintenance Manual, GDL 82 Mooney M20()Series STC (Garmin document 190-01810-11), for troubleshooting, if needed.5.3.2 Internal GPS/SBAS ReceiverThe GPS checkouts described in this section are applicable for installations of the GDL 82 unit withinternal GPS/SBAS receiver (Garmin P/N 011-03946-40). GDL 82 and transponder should be poweredon while all other avionics be turned off at the start of this test.NOTEAfter initial installation, the initial acquisition of GPS position can take up to 20 minutes.Subsequent acquisitions should not take as long.NOTEA VHF COM interference check must be completed on all GDL 82 with GPS/SBAS installations.