Garmin GPSMAP 175 - Manual (Page 74)

A. Select the desired
format from the
NMEA field. The
baud rate will
automatically be set
to the appropriate
speed.
B. After entering a
DGPS frequency, set
the bit rate to the
speed indicated on the USCG station chart. DGPS coverage, frequencies, and bit
rates are available from the Coast Guard.
SETUP MENUS
NMEA & DGPS Setup
If you are using an NMEA interface format, the NMEA format must be
specified in the NMEA format field that will automatically appear when an
NMEA option is selected. The appropriate baud rate will be set automatically.
To select a NMEA format:
1. Select a NMEA IN/OUT format from the options page.
2. Highlight the NMEA Format field and press T.
3. Select a NMEA sentence format and press T.
4. The baud rate will automatically be set to the appropriate speed. If you
have selected an NMEA IN/OUT setting, you must use the same NMEA
format for both the input and output device.
Tuning DGPS Stations
If the I/O Format is set to accept RTCM input/NMEA Output for connecting
a differential-ready GPS beacon receiver, you will need to tune a frequency in
the tuning field and select a bit rate. The default frequency will be 304.0 kHz,
with a bit rate of 100 bps, or the last DGPS frequency/bit rate selected.
To tune a DGPS frequency:
1. Select the ‘RTCM In/NMEA Out’ format from the options page.
2. Highlight the beacon receiver frequency field and press T.
3. Enter the desired frequency and press T. If you are using an
automatically-tuned DGPS receiver, you may enter 000.0 for
the frequency.
4. Press T to select a bit rate. Five bit rates are available: 0 (used for
automatically-tuned DGPS receivers), 25, 50, 100 and 200 bps. Press T to
confirm. The DGPS status, along with the signal-to-noise ratio of the tuned
station, will be displayed at the bottom of the page.
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175 Manual 7/31/98 3:57 PM Page 70