GNS 400W Series Installation Manual Page 2-3190-00356-08 Rev. G2.3.2 Multiple Baro-Corrected Altitude SourcesThe 400W Series can accept baro-corrected altitude from an ARINC 429 ADC, ARINC 429 EFIS,RS-232 FADC, and GTX 33/330 transponder.If multiple sources of baro-corrected altitude data are supplied to the 400W Series unit, only valid datafrom the highest priority source is used. If the highest priority source becomes unavailable, data is takenfrom the next-highest priority source. The priorities of the baro-corrected altitude sources are as follows(from highest to lowest):1. ARINC 429 ADC2. ARINC 429 EFIS3. ARINC 429 from GTX 33/3304. RS-232 FADC2.3.3 Multiple Heading SourcesThe 400W Series can accept heading data from an ARINC 429 INS/IRU, ARINC 429 EFIS, GAD 42,EHSI, GTX 33/330 transponder, ARINC 429 traffic advisory system, RS-232 FADC, and RS-232WX-500 Stormscope.If multiple sources of heading data are supplied to the 400W Series unit, only valid data from the highestpriority source is used – preference is given to true heading (ARINC 429 label 314) if both true heading(label 314) and magnetic heading (label 320) are received. If the highest priority source becomesunavailable, data is taken from the next-highest priority source. The priorities of the heading sources areas follows (from highest to lowest):1. ARINC 429 INS/IRU2. ARINC 429 EFIS3. ARINC 429 from GAD 424. ARINC 429 from Sandel EHSI5. ARINC 429 from GTX 33/3306. ARINC 429 traffic advisory system7. RS-232 FADC8. RS-232 WX-500 Stormscope