190-00734-11 GTX 33X and GTX 3X5 ADS-B Maintenance ManualRev. 6 Page 3-9Figure 3-5 GNS 480 Transponder Control3.4 GTX 335R/345R with Legacy G1000With specific installations, the GDU 1XXX (of the G1000 system) provides control and operation of theremote mounted GTX 335R/345R units. Figure 3-6 and figure 3-7 display screen shots of the GTX controlpages associated with the G1000 system.Refer to the specific aircrafts pilot guide for generic G1000 transponder control and functionality. Inaddition to the generic transponder operation, functionality has changed to incorporate the GTX 3X5interface as follows.Functions:GND The GND soft key is unavailable with the GTX 3X5 transponders.“XPDR GND UNAVL” will annunciate any time the GND soft key ispressed and the unit will revert to the previous mode the unit was in priorto the GND soft key being pressed.ADS-B TX The transmission of the ADS-B information is enabled/disabled bypressing the ADS-B TX soft key. ADS-B transmission defaults toenabled at each power cycle. In older GDU 1XXX software versions, theADS-B TX soft key is not available; this function defaults to enabled. Donot disable ADS-B transmission unless requested by ATC.Annunciations:ADS-B Fail Any time the ADS-B Out system fails or the GPS signal is degraded, anADS-B Fail message will annunciate.XPDR GND UNAVL Any time the GND soft key is pressed the advisory message willannunciate to alert the ground mode is no longer available.
