Furuno 841 MARK-2 - Manual (Page 28)

16
2.21 Echo Trails
You can show the trails of targets in after-
glow. This function is useful for alerting you
to possible collision situations.
Starting echo trail
Press the [TRAIL] key to start the echo trail
function. Afterglow starts extending from
targets and "TRAIL" and the echo trail time
appear at the top right-hand corner of the
display. Press the key again within 3 sec-
onds to select a different trail time, among
15 sec, 30 sec, 1 min, 3min, 6 min, 15 min,
30 min, and continuous. In continuous plot-
ting the time elapsed appears at the top right
corner on the display.
Note: If the range is changed, trails are painted
anew with the newly selected range.
True trails Relative trails
(requires gyro)
Figure 2-17 Appearance of echo trails
Fixed time trails
When the elapsed time clock counts up to
the trail time selected, the elapsed time dis-
play freezes. The oldest portions of trails are
erased so only the latest trail, equal in length
to the trail time selected, is shown. Then,
trails start extending again. For example, the
one minute trail time is selected. When the
elapsed time display freezes at 60 seconds,
all but the latest one minute of trails are
erased and then trailing continues.
Continuous trail
The maximum continuous trail time is 99
minutes and 59 seconds. When the elapsed
time clock counts up to that time the elapsed
time display is reset to zero all trails are
erased and then trailing is restarted.
Adjusting brilliance of afterglow
The brilliance of the trails' afterglow can be
set on the Backlight/Brilliance menu.
1) Press the [MENU] key.
2) Select Backlight/Brilliance and press the
[ENT] key.
3) Select Echo Trails.
4) Select brilliance.
5) Press the [ENT] key followed by the
[MENU] key.
Canceling echo trails
Press the [TRAIL] key to erase the TRAIL
indication.
2.22 The Navigation Data
Display
Navigation data can be displayed at the
screen bottom if this radar receives naviga-
tion input in NMEA 0183 format. Naviga-
tion data includes
• position in latitude and longitude or Lo-
ran-C time differences (TDs)
• bearing and range to a waypoint selected
on the navigator
• cross track error (XTE—the amount in
nautical miles and the direction the ves-
sel if off course)
• depth
• speed.
If the navigation data include the destina-
tion data, waypoint position is denoted on
the radar display by a dashed ring.