Furuno 851 MARK-2 - Manual (Page 22)

2-13
The guard alarm is a useful anti-collision aid,
but does not relieve the operator of the
responsibility to also keep a visual lookout
for possible collision situations. The alarm
should never be used as the sole means for
detecting possible collision situations.
CAUTION
Selecting guard zone type
The guard alarm can be set to sound on
targets entering (guard in) or exiting (guard
out) the guard zone. Select type of guard
zone as follows.
1. Press the [MENU] key to display the
menu.
2. Press the omnipad at 6 o’clock to
select Mode & Function and press the
[ENT] key.
3. Press the omnipad at 6 o’clock to
select Alarm Mode.
4. Press the omnipad at 3 o’clock/9
o’clock to select IN or OUT as
appropriate.
5. Press the [ENT] key followed by the
[MENU] key.
Dashed line:
no alarm
IN ALARM OUT ALARM
Guard
zone
Figure 2-14 In and out alarms
Setting the guard zone
1. Mentally create the guard zone you
want to display. See Figure 2-15 (1).
2. Operate the omnipad to set cursor on
top (bottom) left edge of the guard zone.
Press the [GUARD] key. *G (IN) (or G
(OUT)), with asterisk blinking, appears
at the top right-hand corner on the
display. (The asterisk indicates the
guard zone is partially set.) See Figure
2-15 (2).
3. Operate the omnipad to set cursor on
bottom (top) right edge of the guard
zone and press the [GUARD] key. The
asterisk disappears. See Figure 2-15
(3).
4. Guard zone appears on the display.
See Figure 2-15 (4).
Silencing the audible alarm
Any ships, landmasses, etc. coming into
(or going out of) the guard zone will trigger
the audible alarm and display the guard
zone in reverse video. You can silence the
alarm by pressing the [GUARD] key. When
this is done, G (ACKN) replaces G (IN) (or
G (OUT)).
Press the [GUARD] key again to reactivate
the alarm. G (IN) (or G (OUT)) replaces G
(ACKN).