Functional Descriptions; Power; Main Course Deviation Indicator - Garmin GNS 480 Installation Manaul

Installation Procedures

2.8 Functional Descriptions

2.8.1

Power

Aircraft power is provided to the GNS 480 on several connectors. The GNS 480 will accept input power
from 10 to 36 VDC.
P1-1 Power + (Primary)
P1-16 Power + (Primary)
P1-35 Power + Out (NAV)
P4-1 Power + (COM transceiver)
P7-1 Power + (NAV receiver)
P1-2 Power Ground (Primary)
P1-20 Power Ground (Primary)
P1-37 Power Gnd Out (NAV)
P4-9 Power Ground (COM transceiver)
P7-2 Power Ground (NAV receiver)
Two sets of primary power and ground pins are provided on P1. Both sets MUST be
connected to the aircraft power source or damage to the unit may occur.
Refer to Appendix D for recommended power connections.
2.8.2

Main Course Deviation Indicator

The Main CDI output displays both lateral and vertical deviation from selected course, lateral and vertical
flags and superflags, and TO/FROM indications.
The CDI key on the bezel of the GNS 480 is used to toggle between the display of GPS and VOR/ILS
information on the CDI window and remote CDI. The navigation source is displayed in the CDI window.
The navigation source can optionally be annunciated externally by connecting the GPS Indicator output
(P7-17) and NAV Indicator output (P7-18). The selection of GPS or VOR/ILS navigation sources may be
toggled remotely by momentarily grounding the CDI Select input (P7-8) is (refer to section 2.8.4 for
additional information on the external annunciators and switches).
If the GNS 480 is setup to IGNORE the CDI select key and discrete input (refer to
3.2.1.6), the Main CDI output will always be based on VOR/ILS information, even
though GPS information will be displayed in the CDI window and 'GPS' will be
annunciated beside the CDI key.
Refer to Appendix D for interconnect information.
2.8.2.1 Deviation Outputs
P7-13 Main CDI + Right
P7-14 Main CDI + Left
P7-30 Main GS + Up
P7-31 Main GS + Down
Each deviation output provides ±150 mV full scale and is capable of driving up to a 200Ω load, (i.e. up to
a maximum of five 1kΩ loads connected in parallel).
2-24
CAUTION
NOTE
560-0982-01 Rev L GNS 480 (CNX80) Installation Manual