Ahrs/Iru Interface Check; Gad 42 Interface Check; Lighting Bus Interface Check - Garmin GPS 400W Installation Manual

5.4.6

AHRS/IRU Interface Check

The GNS 400W Series unit can receive heading data from an external source. This check verifies that the
GNS 400W Series unit is receiving data from these units. Ensure that the GNS 400W Series unit is turned
on and in configuration mode. If the following steps do not perform correctly, check the electrical
connections and configuration setup.
1. Go to the Main Inputs 1 page.
If a Sandel EHSI or an ARINC 429 EFIS is also installed, ensure that it is turned off so
that it does not supply heading to the GNS 400W Series unit.
2. Verify that the HDG field displays valid heading data.
3. Remove power from the heading source and verify that the heading in the HDG field is dashed
out.
5.4.7

GAD 42 Interface Check

This check verifies that the GNS 400W Series unit is interfaced with the GAD 42. For the 400W Series
units, the GAD 42 CONFIG page is implemented in main software version 2.20 or higher.
1. Go to the GAD 42 CONFIG page.
2. Verify that STATUS is ACTIVE.
3. Change any of the options to a different number.
4. Verify that after pressing ENT the STATUS field will change to SENDING then change back to
ACTIVE. If the entry reverts to the previous number when ACTIVE is displayed, then refer to
the GAD 42 Installation Manual (P/N 190-00159-00).
5.4.8

Lighting Bus Interface Check

The display and key backlighting on the 400W Series unit can track an external lighting/dimmer bus input
and use it to vary the display and key backlight levels accordingly. This check verifies that the interface
is connected correctly.
When 14 VDC or 28 VDC lighting buses are connected to the 400W Series unit,
connection of the aircraft lighting bus to the incorrect input pins can cause damage to the
400W Series unit. Always start this test with the dimming bus at the lowest setting, and
slowly increase the brightness. If it is noticed that the LIGHTING level displayed on the
400W Series unit does not increase as the lighting is increased in brightness, verify that
the wiring is correct before proceeding.
1. Ensure the lighting bus is set to its minimum setting.
2. Go to the Main Lighting page.
3. Slowly vary the lighting bus that is connected to the 400W Series unit. Verify that the
LIGHTING value displayed on the configuration screen tracks the lighting bus setting.
400W Series Installation Manual
190-00356-02
NOTE
CAUTION
Page 5-27
Rev. G