Garmin GPSMAP 238 Sounder - Manual (Page 98)

88
Reference
Main Menu: Comm tab
To select a transfer mode:
1. Use the ARROW KEYPAD to select ‘Garmin Data Transfer’ in the ‘Serial Data Format’ fi eld.
2. Highlight the ‘Transfer Mode’ fi eld and press ENTER.
3. Use the ARROW KEYPAD to select the desired setting and press ENTER.
You may also adjust the NMEA output to enable/disable certain sentences and adjust the number
of Lat/Lon output precision digits. You must have one of the ports set to NMEA In/NMEA Out to use
this option. Settings will affect both Port 1 and Port 2 NMEA outputs.
To restore the Serial Data Format settings to the default ‘Garmin Data Transfer’:
1. From the Comm tab, press MENU, highlight ‘Defaults’ and press ENTER.
If ‘Garmin DGPS’ or ‘RTCM In/NMEA Out’ format is selected, additional fi elds are provided to con-
trol a Garmin differential beacon receiver directly from your GPSMAP 188/188C/238 Sounder. 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 high-
light the “Beacon” fi eld and press ENTER.
2. Highlight ‘Scan’ and press ENTER. 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.
You may also manually
enter a frequency and
bit rate.
Status Field
SNR and Distance will
show data when signal
is received.
188188C238 Manual Part 2.indd 88 6/30/2003, 3:32:33 PM