190-00726-00 Rev. J Garmin G900X Pilot’s Guide 133AUDIO PANEL AND CNSSYSTEMOVERVIEW FLIGHTINSTRUMENTS EIS AUDIO PANEL& CNS FLIGHTMANAGEMENT HAZARDAVOIDANCE AFCS ADDITIONALFEATURES APPENDICES INDEXSECTION 4 AUDIO PANEL AND CNS4.1 OVERVIEWThe Communication/Navigation/Surveillance (CNS) system includes the audio panel, communication radios,navigation radios, and Mode S transponder. The System Overview Section provides a block diagram descriptionof the Audio Panel and CNS system interconnection.CNS operation in the G900X is performed by the following Line Replaceable Units (LRUs):• Primary Flight Display (PFD) (1 or 2)• Multifunction Display (MFD)• Integrated Avionics Unit (2)• Audio Panel• Mode S Transponder (1 or 2)• Control Unit (optional)The MFD/PFD controls are used to tune the communication transceivers and navigation radios.The Audio Panel provides the traditional audio selector functions of microphone and receiver audio selection.The Audio Panel includes an intercom system (ICS) between the pilot, copilot, and passengers, a marker beaconsystem, and a COM clearance recorder. Ambient noise from the aircraft radios is reduced by a feature calledMaster Avionics Squelch (MASQ). When no audio is detected, MASQ processing further reduces the amount ofbackground noise from the radios.The single or dual Mode S Transponders are controlled with softkeys and the FMS Knob located on the PrimaryFlight Display (PFD). The Transponder Data Box is located to the left of the System Time Box. The data boxdisplays the active four-digit code, mode, and a reply status (Figure 4-1).
