NorthStar Navigation NorthStar 491 manual Understanding the alarms, Setting the fish alarm

Understanding the alarms

The echo sounder’s alarms work just like the other alarms. Their status is updated every second, and their messages are displayed in the following ways:

•at the bottom of the ECHO screen, and also on various windows that may be overlaid onto these screens

•on the ALARMS screen

On this screen, you can manually “clear,” or stop, new alarms, although some are auto-clearing, and you can view old alarms, which are alarms that already have cleared.

To alert you automatically in situations related to echo sounding, you can set three alarms:

•fish alarm

•seabed bottom alarm

•temperature alarm

NOTE:

You also can set the echo sounder to automatically save *FISH##* or *THERM##* waypoints, when fish or a certain temperature are detected, if the fish or temperature alarms are on. To automatically save these waypoints, see ”Number of special waypoints” starting on page 2-14.

Setting the fish alarm

When the fish alarm is on, an alarm sounds if an echo returns from either inside or outside specific upper and lower limits you’ve set.

To set the fish alarm:

1.At the ECHO screen, press MORE.

2.Press ALARM.

3.At the ALARM screen, press FISH ALARM.

The options on the FISH ALARM window are on/off, echo strength level, upper and lower marker depths, and inside or outside markers.

Page 56 491 Echo Sounder Operations Manual