To restart the scan:
1. Press MENU.
2. Highlight Restart Scan, and press ENTER.
To manually enter a frequency and bit rate:
1. With the unit set to Garmin DGPS or RTCM In/NMEA Out,
highlight the Beacon eld, and press ENTER.
2. Highlight User, and press ENTER.
3. Highlight the Frequency or Bit Rate eld, and press ENTER
4. Enter a frequency or bit rate. Press ENTER when nished
When the unit is receiving a DGPS signal, the Signal to Noise Ratio)
(SNR) and Distance elds show data. The SNR range is 0 dB to 30
dB, with 30 being the best. The Distance eld 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 nd the most updated list of frequencies
and coverage areas, contact your local USCG or see their Web site at
www.navcen.uscg.mil/.
Advanced NMEA Output Setup
If you are going to interface the GPSMAP 278 with another piece
of equipment (such as a radar or autopilot), you must set the
unit 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. Highlight the Setup tab on the Main Menu.
2. Select the COM 1 or COM 2 sub tab.
3. Highlight the Serial Data Format eld, and press ENTER.
4. Select NMEA In/NMEA Out, and press ENTER.
88 GPSMAP 278 Owner’s Manual
MAIn Menu > setuP tAb