Garmin GPS 120 - Manual (Page 54)

I/O jETWf-
HONE/NMEn
C3MER 0183 2.0
<1800 baud
I/O SETUP
RTCM/HMEfi
NMER 0183 2.0
<1800 baud
BEOCON REOEIUEk
FREO:
304.0KHZ
RATE!
25bps
MST ________ R,
»R 0dB
Tuning
I/O SETUP
RTCM/NMEfl
NI1ER 0183 2.0
<1800 baud
BEACON RECEIVER
FREQ: 30^.0KHZ
RATE: 25bps
BIST
35.8K»
SNR 38dB
Reteiumg__
The last two format settings allow the GPS 120
to accept RTCM DGPS corrections in RTCM 104
version 2.0 format. The RTCM/NONE format will
allow connection to any manually tuned beacon
receiver with the proper output interface, with the
baud rate selectable from the GPS 120,
Differential GPS is capable of correcting your
calculated position to be within 5-10 meters.
Differential correction transmitters are not avail­
able in all areas, however. Check local area
providers for service coverage.
The RTCM/NMEA selection controls the
GARMIN GBR-21 beacon receiver. Once a RTCM
setting has been selected, the GPS 120 will auto­
matically 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 previ­
ous beacon has been tuned. You may also enter
your own frequency and bit rate if desired.
To enter a DGPS beacon frequency:
1. H ighlight the 'fieq' field and press
2. Enter the desired frequency and press
3. H ighlight the 'rate' field and press
4. Use the a . and ▼ keystoselectthe desired
transm ission rate.
5. Press the key to confirm your entry.
When the GPS 120 is receiving DGPS corrections
from the GBR-21, the ‘beacon received section of the
I/O setup page will display the beacon frequency and
signal strength, as well as the distance from the trans­
mitter to the beacon receiver.
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