Garmin GPS 12 - Manual (Page 52)

Interface Setup: DGPS (continued)
To enter a DGPS beacon frequency:
1. Highlight the ‘FREQ’ field, and press E .
2. Enter the desired frequency, and press E .
3. Highlight the ‘RATE’ field, and press E .
4. Select the desired bit rate (bps), and press E .
Note: The frequency and bit rate fields are disabled
when the ‘RTCM/NONE’ option is selected.
When the GPS 12 is receiving DGPS corrections
from the GBR 21, the ‘BEACON RECVR’ section of the
I/O setup page will display the beacon frequency and
signal strength, as well as the distance from the beacon
transmitter to your present position. 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 bea-
con receiver is selecting a frequency/bit rate and
waiting for signal reception.
• Once a valid beacon signal has been received, a
‘Receiving’ message will be displayed.
• If the beacon signal is received and no correction
data is being received, a ‘No Data’ message will be
displayed.
• If a beacon frequency cannot be tuned and/or no
signal is received, a ‘No Status’ message will be
displayed.
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 page.
The GPS 12 will display one of three alert messages
concerning DGPS operation:
No DGPS Position— there is not enough correc-
tion data available to compute a DGPS position.
No RTCM Input— the beacon receiver is not
properly connected, the baud rates do not match or
no signal is being provided.
RTCM Input Failed— DGPS data was being
received but has been lost.
DGPS
REFERENCE
48
The baud rate is selec-
table for all RTCM and
NMEA interface options.
Alert messages will signal
any problems with DGPS
operation.
GPS12B 1/13/99 4:29 PM Page 48