Garmin GPSMAP 495 - Manual (Page 126)

118 GPSMAP 495 Owner’s Manual
Main Menu > Setup Tab
To manually enter a frequency and bit rate:
1. With the unit set to GARMIN DGPS or RTCM In/NMEA Out, use
the ROCKER to highlight the Beacon field, and press ENTER.
2. Highlight User, and press ENTER.
3. Highlight the Frequency or Bit Rate field, press ENTER, and
enter a frequency or bit rate. Press ENTER when done.
When the unit is receiving a DGPS signal, the SNR (Signal to Noise
Ratio) and Distance fields show data. The SNR range is 0 dB to 30
dB, with 30 being the best. The Distance may or may not show data,
based 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
( www.navcen.uscg.mil) .
Advanced NMEA Output Setup
If you are going to interface the GPSMAP 495 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 selected the unit can take longer than two seconds to update. You
can also set the rate to Fast to output a minimum number of NMEA
sentences at 1-second intervals.
To access the Advanced NMEA Output Setup:
1. Press MENU twice to open the Main Menu.
2. Use the ROCKER to select Setup from the vertical tab list.
3. Select Interface from the row of tabs along the top.
4. Highlight the field below Serial Data Format. Press ENTER.
5. Select NMEA In/NMEA Out. Press ENTER.
6. Press MENU to open the options menu. Select Advanced NMEA
Setup, and press ENTER.