Garmin GPSMAP 168 Sounder - Manual (Page 88)

77
Reference
Main Menu:
Comm Tab
If ‘GARMIN DGPS’ or ‘RTCM In/NMEA Out’ format is selected, additional fi elds are provided to
control a GARMIN differential beacon receiver directly from your GPSMAP 168. You may have the unit
automatically scan for the DGPS beacon signal or you can enter the beacon frequency and bit rate on
the unit and the information will be used to tune the beacon receiver.
To have the unit automatically scan for a frequency:
1. With the unit set to ‘GARMIN DGPS’ or ‘RTCM In/NMEA Out’, use the ARROW KEYPAD to
highlight the “Beacon” fi eld and press ENTER/MARK.
2. Highlight ‘Scan’ and press ENTER/MARK. The numbers in the “Frequency” fi eld will change as the
unit scans from 284 kHz to 325 kHz, 200 bit rate, then 100, at 6-second intervals.
To restart the scan:
1. Press MENU, highlight ‘Restart Scan’ and press ENTER/MARK.
To manually enter a frequency and bit rate:
1. With the unit set to ‘GARMIN DGPS’ or ‘RTCM In/NMEA Out’, use the ARROW KEYPAD to
highlight the “Beacon” fi eld and press ENTER/MARK.
2. Highlight ‘User’ and press ENTER/MARK.
3. Highlight the “Frequency” or “Bit Rate” fi eld, press ENTER/MARK, then enter a frequency or bit
rate and press ENTER/MARK when done.
The “Status” fi eld will show one of the following:
• Tuning— unit is attempting to tune to the specifi ed frequency and bit rate.
• Scanning— unit is automatically scanning through the frequencies and bit rates.
• Receiving— unit is receiving DGPS signal and ready for operation.
• Check Wiring— unit is not making connection with DGPS receiver.
When the unit is receiving a DGPS signal, the “SNR” (Signal to Noise Ratio) and “Distance” fi elds
will show data. The SNR range is 0dB to 30dB, with 30 being the best. The Distance may or may not
show data, depending upon the signal being broadcast from the DGPS site.
You may also manually enter a
bit rate and frequency.
Status Field
SNR and Distance will show data
when signal is received.
168 Manual Part 2.indd 77 11/18/2002, 3:38:00 PM