Changing The Ppi Position; Using The Radar Guard Zones - NorthStar Multi-Function Unit M121 Installation And Operation Manual

18-10 Changing the PPI position

You can move the PPI (Plan Position Indicator)
centre to a different location if you are in
Relative motion mode. (If you are in True
motion mode, the radar automatically positions
the PPI centre.)
To change the PPI position:
1 From the radar window, press MENU then
select Position.
2 There are three choices:
• Centre. The PPI centre is in the centre
of the radar window so that all other
objects move relative to your boat.

18-11 Using the radar guard zones

Use either or both of the two radar guard zones
and alarms to notify you when a target enters
or exits a specified area around your boat.
You can customize the size and shape of the
radar guard zones and set up alarms.
1. From the radar window, press MENU then
select Guard zone.
18-11-1 Turning a radar guard zone on or off
Two radar guard zones are available. You can
turn either or both on or off.
To turn a radar guard zone on or off:
1 From the radar window, press MENU then
select Guard zone.
2 Select Zone. There are two choices:
• 1 selects radar guard zone 1.
• 2 selects radar guard zone 2.
68 Northstar M121/M84 Installation and Operation Manual
• Look Ahead. The PPI centre is positioned
so that the radar window is offset from
the centre to give you the maximum
view ahead.
• Set. Offset the PPI centre in the radar
window. (This works only when you are
using relative motion (RM) mode). Use
the arrow keys to move the PPI centre
to the new position then press
confirm. The new position must allow
most of the radar sweep to appear on the
radar window; if it doesn't, the PPI centre
will be moved as close as possible to the
desired position.
18-11-2 Displaying the area covered by a radar
guard zone
1 From the radar window, press MENU then
select Guard Zone.
2 Select Zone then radar guard zone 1 or radar
guard zone 2.
3 Set Enable to (show the radar guard zone)
or (hide the radar guard zone).
18-11-3 Change the setting for a radar guard
zone alarm
When a radar guard zone is on, the guard zone
alarm is set automatically but you can change
the setting to suit your preferences.
1 From the radar window, press MENU then
select Guard Zone.
2 Select Zone then radar guard zone 1 or radar
guard zone 2.
3 Select Alarm when. There are three choices:
• Enter sounds the alarm only when a
target enters the radar guard zone.
• Exit sounds the alarm only when a target
leaves the radar guard zone.
• Both sounds the alarm when a target
enters or leaves the radar guard zone.
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ENTER