Garmin GPS 40 - Manual (Page 51)

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. Use the U and D keys to select the desired
transmission rate.
5. Press the E key to confirm your entry.
When the GPS 40 is receiving DGPS corre c t i o n s
f rom the GBR-21, the ‘beacon receiver’ section of the
I/O setup page will display the beacon fre q u e n c y a n d
signal strength, as well as the distance from the trans-
mitter to the beacon re c e i v e r.
At the bottom of the beacon receiver field, a sta-
tus message will constantly 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, the
status message will display a ‘receiving’
message.
• If a beacon signal is tuned and no corre c t i o n s
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 40 will also display alert messages con-
c e rning DGPS operation through the message page.
Three DGPS messages may appear:
No DGPS Position indicates that not
enough data is available to compute DGPS
position.
No RTCM Input indicates that the beacon
receiver is not properly connected or the
baud rates do not match.
RTCM Input Failed indicates that DGPS
data was being received but has been lost.
45
The GARMIN GBR 21
is the recommended
beacon receiver for use
with the GPS 40.
Other RTCM 104 v. 2.0
receivers are compatible
with the GPS 40, but
may not provide com-
plete on-screen status
or tuning control.
Beacon Receiver Status
Reference
Beacon
Receiver Data
40 rev B 8/6/98 1:48 PM Page 45