Interfaces; Audio Panel; Altitude Source; Heading Source (Optional) - Garmin GDL 88 Pilot's Manual

6.2

Interfaces

6.2.1

Audio Panel

Traffic alert audio output is interfaced to a required audio panel with a
compatible unswitched unmuted audio input.
6.2.2

Altitude Source

The GDL 88 requires the use of an ownship pressure altitude for transmission
of required ADS-B Out data values and to calculate the vertical separation and
vertical closure from target aircraft.
6.2.3

Heading Source (optional)

The GDL 88 can optionally use heading for the purpose of correlating ADS-B
traffic and traffic received from the external traffic system. HSDB and ARINC 429
digital heading is provided to the GDL 88 from any compatible magnetic heading
source. Multiple heading sources may be connected to the GDL 88.
6.2.4

GPS Position Source

The GDL 88 uses the ownship GPS position for creation of the ADS-B Out
messages as well as the receipt and tracking of ADS-B In targets. The GDL 88
without the internal GPS WAAS requires at least one compatible GPS position
source be installed, while the GDL 88 with the internal GPS WAAS engine may
optionally be interfaced with compatible sources.
6.2.5

Radar Altimeter (Optional)

The GDL 88 can optionally be interfaced with a radar altimeter to drive the
sensitivity level of the Conflict Situational Awareness (CSA) application.
6.2.6

Traffic Mute (Optional)

The GDL 88 can optionally interface with a pilot controlled switch to
acknowledge an active Conflict Situational Awareness (CSA) alert and mute the
associated aural alert. This momentary switch only mutes the current CSAs and
does not act as an inhibit for future CSA aural annunciations.
6-2
Garmin GDL 88 ADS-B Transceiver Pilot's Guide
190-01122-03 Rev. C