Annunciator Outputs - Garmin GNS 480 Installation Manaul

Installation Procedures
2.8.7

Annunciator Outputs

Installations in conformance with the requirements specified in this installation manual
may not require the use of any external annunciators, since all annunciations are provided
on the GNS 480 front panel. Refer to 2.5.3 to determine whether or not external
annunciators are required.
All of the annunciator outputs duplicate annunciations available on the front of the GNS 480. These can be
used to drive annunciator lamps to make the annunciation available remotely (such as in the pilot's
primary field of view). All of these outputs are active low (i.e. grounded when active, and open
otherwise). Each is an open collector output capable of sinking up to 400 mA. These outputs are normally
open and are only grounded under the conditions described herein.
2.8.7.1 GPS / NAV Annunciations
P7-17 GPS Indicator Out
P7-18 NAV Indicator Out
The GPS Indicator Out (P7-17) will be grounded when GPS is being used as the navigation source to drive
the Main CDI, and open otherwise. The NAV Indicator Out (P7-18) will be grounded when VOR/ILS is
being used as the navigation source to drive the Main CDI, and open otherwise.
If external annunciators are used for the GPS/NAV annunciation, it is recommended that the GPS
annunciator is labeled "GPS" in white text, and the NAV annunciator is labeled "NAV" in green text.
Alternately, the annunciator may be labeled with "GPS" in black text on a white background, and "NAV"
in black text on a green background. Refer to 2.5.3.2 for additional information on source selection
annunciators.
2.8.7.2 Back Course Annunciation
P7-15 Back Course Out
The Back Course Out will be grounded when the back course localizer mode is enabled.
If an external annunciator is used for back course annunciation, it is recommended that the back course
annunciator be labeled "BC" in amber text.
2.8.7.3 Dead Reckoning Annunciation
P5-60 Dead Reck Annc
The Dead Reck Annc output is grounded whenever the GNS 480 is in dead reckoning mode (i.e. whenever
the GPS position is lost and the last-known groundspeed is > 3kts).
If an external annunciator is used for dead reckoning annunciation, it is recommended that the dead
reckoning annunciator be labeled "DR" in amber text.
2.8.7.4 Approach Annunciation
P5-61 Approach Annunciate
The Approach Annunciate output is grounded when performing approach navigation and approach is
active.
If an external annunciator is used for approach annunciation, it is recommended that the approach
annunciator be labeled "APPR" in green text.
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NOTE
560-0982-01 Rev L GNS 480 (CNX80) Installation Manual