Serial Interfaces - Garmin GNS 480 Installation Manual

Installation Procedures
2.8.9.5 Com User List Switch
P1-15 UP Discrete In
P1-33 DOWN Discrete In
The Com User List inputs are momentary, active-low discrete inputs and are used to display the Com
User List and select a frequency. When not displayed, a momentary grounding on either of these inputs
causes the Com User List window to be displayed. When the Com User List window is displayed, a
momentary ground on the UP Discrete In (P1-15) causes the highlighted frequency to move up to the
next frequency in the list. A momentary ground on the DOWN Discrete In (P1-33) causes the highlighted
frequency to move down to the next frequency in the list. Once selected, the frequency can be made
active by pressing the Com Flip-Flop button.
2.8.9.6 Suspend Switch
P5-76 Suspend In
The Suspend In input suspends automatic sequencing of waypoints in the active flight plan. A
momentary ground on this input performs the same function as pressing the SUSP key on the GNS 480
bezel.
2.8.9.7 Audio Inhibit In
P5-77 Audio Inhibit In
The Audio Inhibit In is used to inhibit the GNS 480 audio messages. A ground on this input causes GNS
480 audio messages not to be played; if this input is open GNS 480 audio messages will be played. Any
audio messages that are inhibited because of this input will not be played when the audio inhibit
condition is removed.
The Audio Inhibit input will not inhibit the momentary tone that is played by the GNS
480 whenever a status message is available. This tone can be disabled by the user via the
system configuration page.
2.8.10 S I
ERIAL NTERFACES
2.8.10.1 RS232 / RS422
The GNS 480 provides five bi-directional RS232 serial interfaces, two receive-only RS232 serial
interfaces and one bi-directional RS422 serial interface for making optional connections. The serial port
can be used for connecting to:
Resolvers, indicators, or electronic flight instruments that accept serial data
SL30 for Comm/NAV frequency transfers and DME distance from the database
MX20 to display VOR data on a map and database interface
A second GNS 480
Serial interface specifications are included in Appendix B.
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NOTE
560-0982-01 Rev A GNS 480 (CNX80) Installation Manual