(Red) + 10-35 VDC
(Black) - Ground (Power/Data)
(Blue) Port 1 Data OUT
(Brown) Port 1 Data IN
(White) Port 2 Data IN (N/C)
(Green) Port 2 Data OUT
(Yellow) Alarm Low
GPS/NMEA
Device
RXD +
NMEA Device
10-35 Volts DC
Power
and RXD -
RXD +
TXD +
Alarm Relay
100ma max
coil current
To Transducer
To Unit
DC Positive
(RX COM 1)
(TX COM 1)
(RX COM 2)
(TX COM 2)
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.
You can download a copy of Garmin's proprietary
communication protocol document from the Support
section of our Web site at www.garmin.com.
Complete information concerning 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.
www.nmea.org
G
ETTING
S
TARTED
>
I
NSTALLATION
Fishfinder 250/250C Owner’s Manual
9
