Garmin GPS II Owner's Manual page 86

REFERENCE
The message page will alert
you to any problems relating to
DGPS operation. You may also
monitor the DGPS status from
the status field on the interface
setup page.
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When the GPS II 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' message will be displayed.
The GPS II will also display one of three alert messages concerning DGPS opera-
tion through the message page:
No DGPS Position— not enough data is available to compute a DGPS posi-
tion.
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.