Page 3-4 GTN 625/635/650 TSO Installation ManualRev. C 190-01004-023.3.4 Multiple Indicated Airspeed SourcesThe GTN unit can accept indicated airspeed data from multiple ARINC 429 and RS-232 sources. Ifmultiple sources of indicated airspeed data are supplied to the GTN, only valid data from the highestpriority source is used. If the highest priority source becomes unavailable, data is taken from the next-highest priority source. Priorities of the indicated airspeed sources are as follows from highest to lowest:1. ARINC 429 label 206 from GDU Format 12. ARINC 429 label 206 from Airdata/AHRS3. ARINC 429 label 206 from Data Concentrator4. RS-232 bus from FADC Format 1 or Airdata Format 13.3.5 Multiple True Airspeed SourcesThe GTN unit can accept true airspeed data from multiple ARINC 429 and RS-232 sources. If multiplesources of true airspeed data are supplied to the GTN, only valid data from the highest priority source isused. If the highest priority source becomes unavailable, data is taken from the next-highest prioritysource. Priorities of the true airspeed sources are as follows from highest to lowest:1. ARINC 429 label 210 from Airdata2. ARINC 429 label 210 from Airdata/AHRS3. ARINC 429 label 210 from GDU Format 14. ARINC 429 label 210 from EFIS Format 25. ARINC 429 label 210 from GAD Format 16. ARINC 429 label 210 from Data Concentrator7. RS-232 bus from FADC Format 1 or Airdata Format 13.3.6 Multiple VLOC Selected Course SourcesThe GTN unit can accept VLOC selected course data from the sources list below. If multiple sources ofVLOC selected course data are supplied to the GTN, only valid data from the highest priority source isused. If the highest priority source becomes unavailable, data is taken from the next-highest prioritysource. Priorities of the VLOC selected course sources are as follows from highest to lowest:1. ARINC 429 label 100 from EFIS Format 42. ARINC 429 label 110 from GAD Format 13. TO/FROM course from an Omni-Bearing Selector (OBS) control