Furuno FAR-21 7-BB Series, Operator'S Manual

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1. RADAR OPERATION
1-39
1.24 Setting a Target Alarm
The target alarm serves to alert the navigator to targets (ships, landmasses, etc.)
entering a set area, with audible and visual alarms.
The guard alarm zone has a fixed
width of 0.5 nm in the radial direction
(depth) and is adjustable from 3.0 to
6.0 nm (guard zone 1) and any
distance (guard zone 2). On the
Non-IMO radar the boundaries can be
set at any distance. On any radar type
the sector of the zone can be set from
0 to 360 degrees in any direction.
1.24.1 How to set a target alarm zone
The procedure which follows shows how to set a target alarm zone using the
figure below as an example.
1. Roll the trackball to choose the ALARM1 or ALARM2 box, whichever alarm
you wish to set.
ALARM 1
ALARM 2
ALARM boxes
2. Push the left button. The cursor jumps into the effective display area and
“SET” appears inside the ALARM box chosen.
3. Roll the trackball to place the cursor on point “A” and then push the left
button.
4. Roll the trackball to place the cursor on point “B” and then push the left
button. “WORK” replaces “SET” in the ALARM box. The guard alarm zone’s
lines are dashed and blue.
000 010
020
030
040
050
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070
080
090
100
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340 350
Guard alarm zone
A
B
Target alarm zone
CAUTION
•
The alarm should not be relied upon as
the sole means for detecting possible
collision situations.
•
A/C SEA, A/C RAIN and GAIN controls
should be properly adjusted to be sure
the alarm system does not overlook
target echoes.