Audio Panel  -  Traffic alert audio output is interfaced to a required audio panel with a compatible unswitched, unmuted audio input

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.

TAS/TCAS Traffic Systems - The GDL-88 will interface with the GTS-800/820/850, Skywatch, Skywatch HP, and Avidyne TCAD.

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.

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.

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.

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.