Garmin Personal Navigator GPS 45XL Owner's Manual & Reference page 56

Reference
Interface Setup
DGPSInterface
Once a RTCM option is
selected, you must manually
tune the beacon re c e i v e r
from the frequency field.
The message page will alert
you to any problems relat-
ing to DGPS operation. You
may also monitor the DGPS
status from the status field
on the interface setup page.
52
DGPS Interface (continued)
The RTCM/NMEA selection controls the GARMIN GBR-
21 differential beacon receiver. Once a RTCM setting has
been selected, the GPS 45XL will either automatically try to
tune the last frequency and bit rate you selected or will
switch to the default frequency of 304.0 kHz with a bit rate
of 100 bps if no previous beacon has been tuned. You may
also enter your own frequency and bit rate if desired.
To enter a DGPS beacon frequency:
1. Highlight the 'freq' field and press
2. Enter the desired frequency and press
3. Highlight the 'rate' field and press
U D
4. Use and
E
5. Press the
When the GPS 45XL is receiving DGPS corrections
from the GBR-21, the 'beacon receiver' section of the I/O
setup page will display the beacon frequency and signal
strength, as well as the distance from the transmitter to the
beacon receiver. At the bottom of the beacon receiver field,
a status message will keep you informed of DGPS activity:
• A 'tuning' message will be displayed while a beacon
signal is being tuned.
• Once the beacon signal has been tuned, a 'receiving'
message will be displayed.
• If a beacon signal is tuned and no corrections are
being received, a 'no data' message will be displayed.
• If a beacon signal cannot be tuned, a 'no status' mes-
sage will be displayed.
The GPS 45XL will also display one of three alert mes-
sages concerning DGPS operation through the message
page:
No DGPS Position— not enough data is available to
compute a DGPS position.
No RTCM Input— the beacon receiver is not properly
connected or the baud rates do not match.
RTCM Input Failed— DGPS data was being received
but has been lost.
E
E
E
to select the desired transmission rate.
key to confirm your entry.
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