Garmin G3X Pilot’s Guide190-01115-00 Rev. G 115CNS InterfaceSystemOverviewFlightInstruments EISCNSInterfaceGPSNavigationFlightPlanningHazardAvoidanceAdditionalFeaturesIntegratedAutopilot Annun/Alerts Appendix IndexGROUND MODEGround Mode is normally selected automatically when the aircraft is on the ground.The transponder powers up in the last mode it was in when shut down. To manuallyselect Ground Mode, press and hold the STBY Softkey. A green GND indication andtransponder code appear in the mode field of the Transponder Data Box and the STBYSoftkey becomes the GND Softkey. In Ground Mode, the transponder does not allowMode A and Mode C replies, but it does permit acquisition squitter and replies todiscretely addressed Mode S interrogations.Deselect (press) the GND Softkey to return to Standby Mode.STANDBY MODE (MANUAL)Standby Mode can be selected at any time by pressing the STBY Softkey. In Standby,the transponder does not reply to interrogations, but new codes can be entered. WhenStandby Mode is selected, a white STBY indication and transponder code appear in themode field of the Transponder Data Box.MANUAL ON MODEON Mode can be selected at any time by pressing the ON Softkey. ON Modegenerates Mode A and Mode S replies, but Mode C altitude reporting is inhibited. InON Mode, a green ON indication and transponder code appear in the mode field ofthe Transponder Data Box.ALTITUDE MODE (AUTOMATIC OR MANUAL)Altitude Mode is automatically selected when the aircraft becomes airborne. AltitudeMode may also be selected manually by pressing the ALT Softkey.If Altitude Mode is selected, a green ALT indication and transponder code appearin the mode field of the Transponder Data Box, and all transponder replies requestingaltitude information are provided with pressure altitude information.REPLY STATUSWhen the transponder sends replies to interrogations, a white R indication appearsmomentarily in the Transponder Data Box.
