Raymarine L1250D, Owner'S Handbook Manual

Page: 139 / 246

Chapter 6: Sonar Operations 6-9
Usi
ng VRM
to
Det
erm
in
e De
p
th
&
Di
st
an
ce
fr
om
Bo
at
External Alarms
All SeaTalk system alarms (except autopilot, shallow, and deep) alarms are
received and displayed on the Fishfinder. You can silence these alarms by
pressing any key. No other action is taken by the Fishfinder except to silence
the alarm.
➤
To set an alarm
1. Press the
ALARMS
key. The alarms soft keys are displayed.
2. For the shallow or deep alarms, press the
SHALLOW ALARM
or
DEEP ALARM
soft key, and then use the up or down soft keys to change the alarm limit.
Press the up arrow (right) soft key to select deeper water; press the down
arrow (left) soft key to select shallower water.
The depth is in the units selected in system set up (see section
Section 4.4 )
3. If desired, press the
ALARM OFF ON
soft key to toggle the alarm on or off. If
you turn the shallow or deep alarm off, its value is retained and will be used
when you turn the alarm on again.
4. Press
ENTER
or
CLEAR
to save the changes and clear the list.
➤
To silence an alarm and clear the alarm message, press any key.
6.4 Using VRM to Determine Depth & Distance from Boat
The VRM (variable range marker) key is used on the Fishfinder to determine
the depth and distance-behind-boat of an object on the display. The
VRM
function is available on the scrolling fishfinder display, bottom lock and zoom
windows.
A VRM is displayed as a cross hair with height and width of the display
window. The center of the crosshair is the reference for which depth and
distance-behind-boat are displayed. You can use the context-sensitive cursor
to move the VRM over a particular object.
Depth is displayed, in the system units, on the right hand edge of horizontal
line. In the scrolling fishfinder and zoom windows depth is measured from the
surface down. In the bottom lock window, depth is measure from the bottom
up.
Distance-behind-boat is displayed next to the vertical line, at the top of the
window. The VRM distance units correspond to the depth units assigned in the
System Set Up Parameters (see page 4-4) as follows:
DEEP
ALARM
SHALLOW
ALARM
FISH
ALARM
OFF ON
D5031-1
ALARMS
VRM/EBL
81213_1.book Page 9 Monday, March 17, 2003 1:14 PM