Garmin Fishfinder 320C Owner's Manual And Reference Manual page 12

Installation
Wiring and Interfacing
You can download a copy of Garmin's propri-
etary communication protocol document from
the Help and Support section of our web site at
www.garmin.com.
Complete information concern-
ing National Marine Electronics
Association (NMEA) format and
sentences is available for purchase
from NMEA at:
NMEA
Seven Riggs Avenue
Severna Park, MD 21146
U.S.A.
410-975-9425
410-975-9450 FAX
www.nmea.org
4
PIN 1 (red) 10-35 VDC
PIN 2 (black) Ground (Power and Data)
(Cable View)
PIN 3 (blue) Port 1 Data OUT
4
3
5
2
6
PIN 4 (brown) Port 1 Data IN
1
7
PIN 5 (white) Port 2 Data IN (N/C)
PIN 6 (green) Port 2 Data OUT
PIN 7 (yellow) Alarm Low
Note: During a typical installation, only the Red and
Black wires are used. The other wires do not have to
be connected for normal operation of the unit.
Interfacing
The Fishfi nder 320C allows for NMEA 0183, Version 2.3 input/output with a compatible GPS or
navigation device. NMEA Input/Output must be set to 'On' to send/receive data. (see pg. 18). For additional
information on using your Fishfi nder 320C with NMEA devices, see pages 3, 13-14, and 18.
The following are the sentences for NMEA 0183, version 2.3:
Input — GPBOD, GPBWC (only used if RMB not present), GPGGA, GPGLL (only used if GGA not present),
GPRMB, GPRMC, GPXTE (only used if RMB not present)
Output — SDDBT, SDDPT, SDMTW, SDVHW, SDWPL* (only if a waypoint is "marked" in Pointer Mode)
*Garmin GPS units will accept the SDWPL (WPL) NMEA sentence and create a waypoint (saved location) at that position (see pg.
13). For compatibility with other brands of GPS or NMEA capable navigation devices, check with that manufacturer to see if their unit
accepts/stores NMEA 0183 SDWPL sentences/waypoints. The Fishfi nder 320C does not store the actual waypoint. Only the receiving
device, if capable, will store the waypoint.
10-35 volts DC
RXD +
TXD +
NMEA Device
RXD +
Alarm Relay
100ma max
coil current
Power
GPS/NMEA
Device
and RXD -