Serial Data Format
—sets the data format to one of the following:
•
Garmin Data Transfer
—provides the proprietary format
used to exchange data with a computer or another Garmin
GPSMAP 378/478. Garmin Data Transfer is disabled when
the USB is connected, and the unit automatically switches to
USB format. When the
USB is disconnected, the USB field
changes to Transfer Mode.
•
GARMIN DGPS
—connects the GPSMAP 378/478 with a
Garmin DGPS beacon receiver.
•
Garmin Remote Sonar
—connects the GPSMAP 378/478
with a GSD 21 or GSD 20 Sounder Module and transducer.
•
NMEA In/NMEA Out
—supports the input/output of
standard NMEA 0183 version 3.01 data and sonar NMEA
input support for the DBT, DSE, DPT, MTW, and VHW
sentences.
•
RTCM In
—allows DGPS input using a standard RTCM
format.
•
RTCM In/NMEA Out
—allows DGPS input using a standard
RTCM format and also provides NMEA 0183 version 3.01
output.
•
RTCM In/Text Out
—allows Differential GPS (DGPS) input
using a standard RTCM format and also outputs simple text
data that includes data, time, location, and velocity.
•
Text Out
—allows the unit to output simple text data that
includes data, time, location, and velocity. The Baud can be
set to 1200, 2400, 4800, or 9600.
•
None
—provides no interfacing capabilities.
If you select GARMIN DGPS or RTCM In/NMEA Out format,
you can control a differential beacon receiver directly from your
GPSMAP 378/478 using the Interface sub tab. You can have the unit
automatically scan for the DGPS beacon signal, or you can enter the
beacon frequency and bit rate on the unit, and the information will
be used to tune the beacon receiver. If you use a DGPS receiver,
WAAS capability is automatically turned off.
To have the unit automatically scan for a frequency:
1. Set the unit to
GARMIN DGPS
or
RTCM In/NMEA Out
.
2. Highlight the
Beacon
field, and press
ENTER
.
3. Highlight
Scan
, and press
ENTER
. The numbers in the
Frequency
field change as the unit scans from 284 kHz to
325 kHz, 200 bit rate, then 100, at 6-second intervals.
2
GPSMAP 378/478 Owner’s Manual
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