When the unit is receiving a DGPS signal, the Signal to Noise Ratio)
(SNR) and Distance fields show data. The SNR range is 0 dB to 30
dB, with 30 being the best. The Distance field may or may not show
data, depending on the signal being broadcast from the DGPS site.
The DGPS beacon transmitters are operated by the United States
Coast Guard (or similar government agency in other countries),
which is responsible for their accuracy and maintenance. For DGPS
transmitter problems or to find the most updated list of frequencies
and coverage areas, contact your local USCG or see their Web site at
http://www.navcen.uscg.mil/.
Advanced NMEA Output Setup
If you are going to interface the GPSMAP 276C with another
piece of equipment (such as a radar or autopilot), the unit needs
to be set to output NMEA data. The NMEA data transmission can
be customized to keep the output rate at two seconds. If too many
NMEA sentences are activated, the unit may take longer than two
seconds to update. You can also set the Output Rate to Fast to output
a minimum number of NMEA sentences at one-second intervals.
To access the Advanced NMEA Output Setup:
1. Press MENU twice to open the Main Menu, and then select
the Setup tab.
2. Select the COM 1 or COM 2 sub tab.
3. Highlight the
Serial Data Format field, and press ENTER.
4. Select NMEA In/NMEA Out, and press ENTER.
5. Press MENU to open the options menu. Select Advanced
NMEA Setup, and press ENTER.
Advanced NMEA Output Setup
Use the Advanced NMEA Output Setup Page to set the output rate,
change the precision of the Lat/Lon minutes, set Waypoint IDs to
names or numbers, and turn on and off the GPS status, the GARMIN
Proprietary sentences, and Waypoint/Route (WPL, RTE).
GPSMAP 276C NMEA Sentence Output (NMEA version 3.01
compliant):
• Always transmitted: GPRMC, GPGGA, GPGLL, GPBWC,
GPVTG, GPXTE, GPRMB
• Switchable sentences: GPGSA, GPGSV, GPWPL, GPRTE
• GARMIN proprietary: PGRME, PGRMZ, PGRMM
88 GPSMAP 276C Owner’s Manual
MAIN MENU > SETUP TAB
