Garmin G900X Pilot’s Guide 190-00726-00 Rev. A1-2SYSTEM OVERVIEW1.1 LINE REPLACEABLE UNITS• GDU 1040 (2) – The left-hand GDU is configured as a Primary Flight Display (PFD) and the right-hand GDUas a Multi Function Display (MFD). Both feature 10.4-inch LCD screens with 1024 x 768 resolution. Thedisplays communicate with each other through a High-Speed Data Bus (HSDB) Ethernet connection. Eachdisplay is also paired with an Ethernet connection to an IAU.• GMA 1347 – The Audio Panel integrates navigation/communication radio (NAV/COM) digital audio, intercom,and marker beacon controls, and is installed between the displays. This unit also provides manual control ofdisplay reversionary mode (red DISPLAY BACKUP Button; see Section 1.5, System Operation) and communicateswith both IAUs using an RS-232 digital interface.• GIA 63W (2) – The Integrated Avionics Units (IAU) function as the main communication hubs, linking allLRUs with the on-side display. Each IAU contains a GPS WAAS receiver, VHF COM/NAV/GS receivers, andsystem integration microprocessors, and is paired with the on-side display via HSDB connection. The IAUs arenot paired together and do not communicate with each other directly.
