Garmin GNC 420A Installation Manual

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Garmin GNC 420A Installation Manual Manual pdf 37 page image

400 SERIES INSTALLATION MANUAL Page 4-9190-00140-02 Rev Q4.5 ANNUNCIATORS/SWITCHES4.5.1 Annunciators/Switches FunctionNOTEInitial certification of the 400 Series units was accomplished without use of any remoteswitches or annunciators, since the same switching and annunciation is available onthe front panel of the 400 Series unit. However, if the 400 Series unit is not installed inthe pilot’s normal field of view, some or all of the remote switches and annunciators maybe required by your certification agency. Appendix B includes an FAA letter grantingpermission to install GNS 430 without external switches and annunciators.4.5.1.1 MESSAGE ANNUNCIATEWhen a new status message is available, the Message Annunciator flashes. When status messages remaineffective, the Message Annunciator illuminates.4.5.1.2 WAYPOINT ANNUNCIATEThe waypoint annunciator output is driven in the following manner:1. When the aircraft is within 10 seconds of reaching the turning point for a course change, thewaypoint annunciator flashes.2. When the aircraft is in a turn, the waypoint annunciator illuminates and remains illuminated untilthe turn is completed.3. When a user arrival alarm is set and the aircraft is within the circle defined by the arrival alarmradius at the arrival waypoint, the waypoint annunciator flashes for 10 seconds.4. When a user arrival alarm is not set and the aircraft is within 10 seconds of reaching the arrivalwaypoint, the waypoint annunciator flashes.4.5.1.3 CDI SOURCE SELECT (GNS 430 Only)This CDI Source Select input may be used to toggle between display of GPS and VOR/LOC/Glideslopeinformation on the MAIN external CDI/HSI. A momentary low on this pin performs the same function aspressing the ‘CDI’ key on the GNS 430 bezel.4.5.1.4 VLOC ANNUNCIATE (GNS 430 Only)This VLOC Annunciate output is driven when the unit is configured with a single CDI/HSI and theVOR/ILS data is being displayed on the CDI/HSI. This output parallels the VLOC annunciator on thedisplay.4.5.1.5 GPS ANNUNCIATE (GNS 430 Only)This GPS Annunciate output is driven when the unit is configured with a single CDI/HSI and the GPS datais being displayed on the CDI/HSI. This output parallels the GPS annunciation on the display.4.5.1.6 OBS MODE SELECTThis OBS Mode Select input may be used to toggle between GPS OBS and GPS AUTO modes ofoperation. A momentary low on this pin performs the same function as pressing the ‘OBS’ key on the 400Series unit.4.5.1.7 AUTO ANNUNCIATEThis Auto Annunciate output is driven to indicate GPS AUTO mode of operation. This output is activewhen neither the OBS nor SUSP annunciations are on the display.4.5.1.8 OBS ANNUNCIATEThis OBS Annunciate output is driven to indicate GPS OBS mode of operation. This output is active whenthe OBS or SUSP annunciation is on the display.4.5.1.9 TERMINAL ANNUNCIATEWhen performing approach navigation, the terminal annunciator is illuminated when operating within 30nautical miles of the departure or arrival airport and the CDI scale is the equivalent or 1.0 nm or less.4.5.1.10 APPROACH ANNUNCIATEWhen performing approach navigation, the approach annunciator illuminates when approach is active.