Garmin Diamond DA40, Maintenance Manual

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G1000/DA40 System Maintenance Manual Page 2-23
190-00303-03 Revision 6
2.8 G1000 System Communications
2.8.1 Flight Instrumentation
The GRS 77 AHRS, GDC 74A Air Data Computer, and GMU 44 Magnetometer are responsible for
providing the G1000 system with flight instrumentation. Data consists of aircraft attitude, heading,
altitude, airspeed, vertical speed, and outside air temperature information, all displayed on the PFD (data
is displayed on the MFD in reversionary mode only).
Primary data outputs from the GRS and GDC are sent directly to the PFD via ARINC 429. Secondary
data paths connect the GRS and GDC to the MFD. Additional communications paths connect the GRS
and GDC to both GIA 63 units, providing quadruple redundant interface.
The GRS 77 receives GPS data from both GIAs, airspeed data from the GDC, and magnetic heading from
the GMU. Using these three external sources, combined with internal sensor data, the GRS accurately
calculated aircraft attitude and heading.
Figure 2-25. Flight Instrumentation Interface