Garmin GDL 90, Руководство по установке

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Installation Procedures
2-18 560-1049-02 Rev. B GDL 90 Installation Manual
2.8.5 Discrete Inputs
The discrete inputs can be used to provide additional status information from aircraft systems or
equipment. All of these inputs are active low (i.e. grounded when active, and open otherwise). Each
input presents a load of greater than 100 k
Ω
.
2.8.5.1 Air/Ground Discrete Input
P2-23 Air/Ground In
The Air/Ground In is used to provide the aircraft air/ground status. The function of this discrete input
can be configured via the APM setup (refer to Section 4, Page 4-2). Using the APM setup, the
Air/Ground In can be configured in one of the following options:
•
An air/ground switch is not installed. For light fixed-wing aircraft only, the air/ground state can
be set automatically based on GPS ground speed. The speed threshold value can be configured in
the APM. Refer to Section 4 for instructions. Otherwise, all aircraft that do not have an
air/ground switch will always report that they are Airborne.
•
A ‘ground’ at the Air/Ground In indicates that the aircraft is on the ground, and an ‘open’
indicates that the aircraft is in the air.
•
A ‘ground’ at the Air/Ground In indicates that the aircraft is in the air, and an ‘open’ indicates
that the aircraft is on the ground.
NOTE
The signal provided by the Air/Ground Input may be overridden by other system inputs,
such as ground speed and/or radio altitude, to guard against switch failure.
2.8.5.2 Audio Inhibit In
P2-5 Audio Inhibit In
The Audio Inhibit In is used to inhibit the GDL 90 audio messages. A ground on this input causes GDL
90 audio messages not to be played; if this input is open GDL 90 audio messages will be played.
2.8.5.3 TCAS Operational Discrete Input
P2-22 TCAS Operational In
The TCAS Operational In is provisioned for future use, to provide operational mode information of an
on-board TCAS system. A ground on this input will indicate that the TCAS system is installed and
operational. An open on this input will indicate that the TCAS is not installed or operational. This
interface is not approved for use and should be left open.
2.8.5.4 TCAS Resolution Advisory Active Discrete Input
P2-4 TCAS RA Active In
The TCAS RA Active In is provisioned for future use, to provide the status of any resolution advisories
that the on-board TCAS may be generating. A ground on this input will indicate that a TCAS resolution
advisory is currently active. An open on this input will indicate that there are currently no active TCAS
resolution advisories. This interface is not approved for use and should be left open.
2.8.5.5 429 Traffic Test Input
P2-2 429 Traffic Test Input
This input discrete provides feedback for the Traffic Test function of a 429 traffic display.