Garmin GPS 92 - Manual (Page 62)

When a NMEA output setting has been selected, a
baud rate of 4800 will automatically appear.
To select a different baud rate:
1. Highlight the baud rate field and press
E
2. Select the desired setting and press
E
.
DGPS Interface Setup
The two RTCM settings allow the GPS 92 to accept
Differential GPS (DGPS) corrections in RTCM 104 version
2.0 format. The ‘RTCM/NONE’ format allows you to con-
nect any manually-tuned beacon receiver with the proper
interface. The baud rate is selectable from the GPS 92. The
‘RTCM/NMEA’ selection allows you to control a GARMIN
GBR 21 beacon receiver directly from the GPS 92.
Once an RTCM setting has been selected, the GPS 92
will automatically try to tune the last frequency and bit
rate selected, or it will switch to the default frequency of
304.0 kHz with a bit rate of 100 bps if no previous bea-
con has been tuned. You may also enter your own fre-
quency and bit rate if desired.
To enter a beacon frequency and bit rate:
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 rate and press
E
.
When the GPS 92 is receiving DGPS corrections, the
‘BEACON RECVR’ section of the interface page will dis-
play the signal strength and distance from the transmitter
to the beacon receiver. A status message will constantly
keep you informed of DGPS activity:
• A ‘Tuning’ message will be displayed while a beacon
signal is being tuned. Once the signal has been
tuned, the message ‘Receiving’ will be displayed.
• If a 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.
GARMIN
GBR 21
DGPS corrections are
accepted in RTCM-104 v.
2.0 format. The GARMIN
GBR 21 is the recommended
beacon receiver for use with
the GPS 92. Other receivers
with the correct RTCM for-
mat may be used, but may
not correctly display status
or allow tuning control
directly from the GPS 92.
DGPS Interface
Once the ‘RTCM/NMEA’
interface option is selected,
you must tune the beacon
receiver from the frequency
field.
Setup Menu:
DGPS Interface
Setup
Reference
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92 manual 4/15/98 3:48 PM Page 56