System Checkout - G - Garmin GNS 480 Installation Manual

Post-Installation Configuration & Checkout
3.3.2 S
YSTEM
The GNS 480 includes a self test that is executed every time the unit is turned on that checks the unit
operation as well as other internal functions. Verify that the unit does not display a failure indication
when turned on.
The GNS 480 must be properly configured prior to performing system checkouts. When
configured correctly, the GNS 480 will annunciate failures that are detected with
interfacing systems when it is first turned on. Any annunciated failures should be
corrected prior to proceeding with the ground checks.
3.3.2.1 GPS Navigation Checkout
Switch on the GNS 480 in the normal mode to complete this part of the checkout – this is accomplished
by either exiting the Ground Maintenance Mode or by turning the GNS 480 OFF and then turning it back
ON.
The GNS 480 requires a "seed" position, time, and date for the GPS sensor to know which satellites to
look for. Once this information is entered it will be saved and updated automatically, so it will not be
necessary to re-enter the information at every start-up. If the GNS 480 is moved a great distance without
being turned on, the seed position may have to be re-entered.
This checkout must be completed with the aircraft moved away from hangars and other
structures that may obstruct the view of the satellites.
3.3.2.1.1 Initial Power-Up
The first time the GNS 480 is used after it is installed, the GPS seed position, UTC time and date must be
entered. Following the display of the main start-up screen, the screen shown in Figure 3-30 will be
displayed for 10 seconds. Press the CHG smart key to allow the position to be edited. The latitude
(degrees) will be highlighted. Use the large, outer knob to select the next or previous editable data field
and turn the small, inner knob to change the current setting. When the position, UTC time and date have
been entered, press the MENU/ENTER key to accept the entries. The Master GPS Reset must be set to
'No'.
The latitude and longitude must be within one degree of the actual position, and the UTC
time (not local time) must be within one minute. If position, time and date are not
entered correctly, GPS acquisition may take up to 20 minutes.
3-30
C – G
HECKOUT ROUND
560-0982-01 Rev A
C
HECKS
NOTE
NOTE
NOTE
GNS 480 (CNX80) Installation Manual