Furuno FR-2805 Series - Manual (Page 75)

2-14
7. Referring to figure below, place the
cursor at the outer left corner of the
area (point A) and press the ENTER
key.
8. Place the cursor at the right edge of
the area (point B) and press the EN-
TER key.
Note: If you wish to create a guard
zone having a 360-degree coverage
around own ship, set point B in almost
the same direction (approx.
±
3
°
) as
point A and press the ENTER key.
9. Press the [1] key followed by the E,
AUTO PLOT MENU key to close the
ARPA 1 menu.
The guard zone as an example shown be-
low appears on the display. Note that the
guard zone has a fixed radial extension
(width) of 0.5 nm. The label GZ is dis-
played in the box at the upper-right on the
screen when guard zone is enabled.
Target in guard zone
is marked by inverted
flashing triangle.
A
B
0.5nm
Deactivating the guard zone
(guard ring)
1. Press the E, AUTO PLOT MENU key
on the plotting keyboard to show the
ARPA 1 menu.
2. Press the [3] key to select menu item
3GUARD RING.
3. Further press the [3] key to select (or
highlight) OFF to deactivate the guard
zone.
4. Press the ENTER key to conclude your
selection followed by the E, AUTO
PLOT MENU key to close the ARPA 1
menu.
Silencing the guard zone (guard
ring) audible alarm
Press the AUDIO OFF key to acknowl-
edge and silence the guard zone audible
alarm.
2.14 Operational Warnings
There are six main situations which cause
the Auto Plotter to trigger visual and au-
ral alarms:
• CPA/TCPA alarm
• Guard zone alarm
• Lost target alarm
• Target full alarm for manual acquisition
• Target full alarm for automatic acquisi-
tion
• System failures
The audible alarm can be set to OFF
through the AUTO PLOT 2 menu.
CPA/TCPA alarm
Visual and aural alarms are generated
when the predicted CPA and TCPA of any
target become less than their preset lim-
its. Press the AUDIO OFF key to acknowl-
edge and silence the CPA/TCPA aural
alarm.
Guard zone (guard ring) alarm
Visual and audible alarms are generated
when a target transits the operator-set
guard zone. Press the AUDIO OFF key
to acknowledge and silence the guard
zone audible alarm. (Refer to paragraph
2.14 Setting a Guard Zone for further in-
formation.)
Lost target alarm
When the system detects a loss of a
tracked target, the target symbol becomes
a flashing diamond ( ) and the label
"LOST" appears at the screen bottom. At
the same time, an aural alarm is produced
for one second.
Press the LOST TARGET key to acknowl-
edge the lost target alarm. Then, the lost
target mark disappears.