Understanding alarms. NORTHSTAR 958

Chapter 11 - Alarms, TideTrack, and Video Display

Understanding alarms

Alarms automatically alert you to certain situations, for example, when you’re approaching a waypoint, or entering an avoidance area, or when you’ve lost position fixes. The 958 displays its alarms in two different ways:

•

• as specific alarm icons on the display screens as alarm messages (with details about the alarm icon) on the ALARMS screen

Also, whenever an alarm icon appears on any screen, an audible alarm will sound if you’ve turned on the alarm audio.

Each alarm has a distinctive beep that’s based on Morse code.

If you’re choosing whether to keep the alarm audio on or off, remember that the audio beep may be a necessity when you’re unable to look at the display screen.

Understanding alarm icons

There are 18 possible alarm icons, depending on the particular alarm condition. For a detailed explanation of these alarm icons, see Table 6 on page 146.

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Figure 8: Alarm icons

Three of these icons—bottom, fish, and temp—will only appear if you’re using the echo sounder (fishfinder); for details, see the Northstar 490 Operations Manual (GM490) .

Two of these icons—radar guard and no radar data—will only appear if you’re using radar.

958 Operator’s Manual, Rev. A

Displaying alarm messages


To display the alarm message associated with the icon, press the STAR key to display the ALARMS screen.

New alarm messages

The word NEW in the RECENT ALARMS box tells you that the alarm shown hasn’t been “cleared” yet (see “Clearing alarms” below). There may also be other uncleared alarms.

Recent alarm messages

The 958 keeps a record of the one most recent alarm from each main category (anchor, avoidance, communications, cross track, and waypoints). This lets you “browse” through the older alarm messages. Each successive press of the CLEAR

ALARM menu key will show you the most recent alarm message from each category.

Clearing alarms

Clearing an alarm means removing the flashing alarm icon as well as the word NEW from the display of that alarm on the

ALARMS screen. To manually clear an alarm (or to see other alarms that may need clearing), press the CLEAR ALARM key on the ALARMS screen.

958 Operator’s Manual, Rev. A Page 145


There are two types of alarms:

•

• “Auto-clear” alarms - These automatically clear after the alarm condition disappears, or in some cases, after a short time-out period (typically about 10 seconds). Most alarms are auto-clearing; however, they can also be manually cleared, if desired.

Alarms that require manual clearing - These will stay onscreen until you clear them on the ALARMS screen.

All of the 958’s alarms are described in Table 6 below.

NOTE:

The following abbreviations are used in Table 6.

For alarm message, ‘NAME’ = name of waypoint.

For “must be cleared,”, N = no, Y = yes

Table 6: 958 alarms

YOUR ANCHOR

MAY BE DRAGGING

Vessel has moved outside the radius limit set in the ANCHOR alarm. This alarm is shown only if you’ve turned it on at the

ALARMS screen and you have pressed the DROP ANCHOR key.

Does not time out.

Y

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Table 6: 958 alarms (continued)

YOU’VE ARRIVED

AT WAYPT: ‘NAME’

Vessel has entered the arrive radius of an active waypoint. This alarm is shown only if you’ve chosen manual waypoint switching, or when you’re navigating to a single waypoint.

Within 10 seconds.

N

YOU’VE ENTERED

AVOID ZONE

Vessel has entered the warning radius of an avoidance waypoint. This alarm is shown only if you’ve turned it on at the

ALARMS screen.

Does not time out. Y

Vessel has switched to the next leg of the route.

Within 10 seconds.

N

NOW NAVIGATING

TO WAYPT: ‘NAME’




YOU’RE CLOSE TO

WAYPT: ‘NAME’

Vessel is within 900 feet of entering the arrive radius of an active waypoint.

Within 10 seconds. N

CROSS-TRACK

LIMITS EXCEEDED

Vessel has exceeded the off-course limit set in the CROSS TRACK alarm. This alarm is shown only if you’ve turned it on at the ALARMS screen.

Does not time out. N

You’ve powered-up the 958 while already in demo mode


!!DEMO MODE IS

ON!!




NO WAAS/DGPS

BIG JUMP IN GPS

POSITION

DGPS or WAAS corrections were previously used, but are now temporarily unusable. This alarm is shown only if you’ve turned it on at the ALARMS screen and

GPS or Phantom loran fixes are being used.


Your displayed GPS position suddenly

“jumps” an unreasonable amount based on the vessel’s speed.


NO GPS POSITION

FIX

GPS position fix is unavailable and GPS or Phantom loran is the chosen position source. This alarm is delayed for three minutes at power-up.

Does not time out.

N




GPS

COMMUNICATION

FAILURE

The 958 hasn’t received any messages from the GPS receiver pod for over 30 seconds.


Position fix from an external loran receiver is unavailable and external loran is the chosen position source. This alarm is delayed for three minutes at power-up.

Does not time out.

N

NO LORAN

POSITION FIX

LORAN

COMMUNICATION

FAILURE

The 958 hasn’t received any messages from the external loran receiver for over

30 seconds.

Does not time out.

Y




YOU’VE PASSED

WAYPT: ‘NAME’

Vessel has passed abeam of the active waypoint — without entering the arrive radius. This alarm only appears if there are NO future waypoints, or if waypoint switching is manual.

Within 10 seconds.

N

BLINK, CYCLE or LOW SNR detected in the external loran used as the position source.


POOR LORAN

SIGNALS

BOTTOM

COLLISION!

Sounder alarms ( only shown on the 958 if sounder is enabled )

Echo sounder detects that the seabed is higher than the specific limit you’ve set

Within 20 seconds after the seabed becomes lower than the limit set.

N

Radar alarms ( only shown on the 958 if radar is enabled )




An object enters the guard zone.

Does not time out.

Y

RADAR GUARD VIO-

LATION

The 958 hasn’t received radar data for several seconds.

When new data comes in.

N

RADAR DATA NOT

AVAILABLE

Changing alarm settings

You can manually adjust four of the 958’s alarms:

•

•

•

• anchor alarm cross track arrive radius

DGPS alarm


958 Operator’s Manual, Rev. A


You can also turn the alarm audio on or off for all of the 958’s alarms

.

Alarm audio

You can turn the alarm audio on so that the 958 will beep when any alarm goes off, or you can turn the audio off completely so that you’ll only see alarm icons and messages displayed on the screen:

1. Press the CURSOR PAD to select ALARM AUDIO, then press the EDIT ALARM menu key.

2. Press the CURSOR PAD to display OFF or ON , then press the ENTER key.

Anchor alarm

The anchor alarm will signal if your vessel moves a certain distance from the position where you pressed the DROP

ANCHOR key. You can turn the anchor alarm on or off, and set the anchor drag distance. The default setting is 0.20 nautical miles (about 1200 feet). You can set the anchor alarm to as little as .01 nm.

Note: Turn off the anchor alarm before you intentionally move away from the anchor-drop point.

To set the anchor alarm:

1. Press the DROP ANCHOR menu key where you’ve dropped the anchor. A waypoint named ANCR is created at this location.

2. Press the ENTER key at the question window.

3. Press the CURSOR PAD to highlight ANCHOR ALARM, then press the EDIT ALARM menu key.

4. Press the CURSOR PAD to turn the alarm to ON .

5. To set the distance your vessel can normally be expected to move on its anchor chain, press the CURSOR PAD right, and use the KEYPAD to enter the distance. Be sure

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Chapter 11 - Alarms, TideTrack, and Video Display to subtract a safety factor to allow for GPS or loran inaccuracy, then press the ENTER key.

Cross-track alarm

The cross-track alarm will signal if your vessel moves beyond a certain distance from the desired track line. You can turn the cross-track alarm on or off, and set the distance from the track line. The default setting is 0.10 nautical miles (about 600 feet).

You can set the cross track to as little as 0.01 nm (about 60 feet).

To set the cross-track alarm:

1. Press the CURSOR PAD to highlight CROSS TRACK , then press the EDIT ALARM menu key.

2. Press the CURSOR PAD to turn the alarm to ON .

3. To set the cross-track distance limit, press the CURSOR

PAD right, and use the KEYPAD to enter the distance, then press the ENTER key.

Arrive radius

The arrive radius is a circle around your current active waypoint. The default setting for the radius is 0.20 nautical miles, or about 1200 feet. You can set the radius to as little as

0.01 nm.

There are two alarms triggered by the arrive radius. If you’re following a route and have chosen automatic waypoint switching, entering the radius makes the 958 switch to the next leg and display the CHANGING alarm icon. If there are no more waypoints in the route, or if you’ve chosen manual waypoint switching, then entering the radius triggers the arrive alarm.

Note: Automatic waypoint switching will also occur if you cross the perpendicular at the end of the current leg.



To set the arrive radius:

1. Press the CURSOR PAD to highlight ARRIVE RADIUS , then press the EDIT ALARM menu key.

2. To set the distance around waypoints, use the KEYPAD to enter the distance, then press the ENTER key.

DGPS alarm

The DGPS alarm will signal if you were using GPS or Phantom loran fixes, but valid, usable beacon or WAAS differential corrections haven’t been received within the time limit you’ve specified in the DGPS data time-out setting. To adjust this setting, see ”Choosing a DGPS corrections time-out” starting on page 176.

To turn on the DGPS alarm, press the CURSOR PAD to highlight DGPS ALARM , then press the EDIT ALARM menu key. Press the CURSOR PAD to turn the alarm to ON , then press the ENTER key.

Setting alarms to honk

You can set the 958 to honk, in addition to the beep, if a honker has been connected to pin #14 on the interface connector. Once you set the anchor alarm to honk, a continuous honking sequence begins when:

• your vessel moves outside the specified anchor-alarm radius

- or -

• the navigation source (for example, GPS) becomes unavailable, so that it’s unsure if you’re inside the radius

To set the anchor alarm to honk:

1. On the ALARMS screen, press the CURSOR PAD to highlight HONK OUTPUT , then press the EDIT ALARM menu key.



2. Press the CURSOR PAD to select ANCHOR ALM.

3. Press the ENTER key.

4. Set the ANCHOR ALARM to ON if it’s currently set to OFF .

5. Press the DROP ANCHOR key.

If your vessel moves outside the anchor-alarm radius, then for the next 10 seconds, the anchor drag icon begins flashing and the alarm automatically beeps (you’ll hear the beeping only if you’ve set the ALARM AUDIO to ON ). The honk sequence then starts for a total of 3.5 minutes: 1 second of honking followed by 14 seconds of silence; 2 seconds of honking followed by 13 seconds of silence; 3 seconds of honking followed by 12 seconds of silence, and so forth, until the honking is up to 14 seconds followed by 1 second of silence.

This 3.5-minute honk cycle repeats forever until you manually clear the anchor alarm. This honk does not automatically clear under any conditions. To clear the alarm, press the STAR key to display the ALARMS screen, then press the CLEAR ALARM key. You may also want to set the anchor alarm back to the OFF setting.

Honking for all alarms

Instead of setting all alarms to only beep, you can set all alarms to honk. This honking starts simultaneously with any flashing alarm icons. After you set all alarms to honk, an alarm causes the 958 to emit a sound for half a second, followed by silence for half a second. This honking sequence stops when the alarms either automatically clear or you manually clear them.

To set all alarms to honk:

1. Press the CURSOR PAD to highlight HONK OUTPUT , then press the EDIT ALARM menu key.

2. Press the CURSOR PAD to select ALL ALARMS , then press the ENTER key.

3. Set the ALARM AUDIO to ON if it’s currently off.


Sound Type

Beep All alarms


Table 7 below describes how to set the anchor alarm and all other alarms to the desired audio.

Table 7: Beep and honk settings for all alarms

Setting(s) Description

Set ALARM AUDIO to ON The 958’s standard alarm beep.

Beep

Honk

Honk

Anchor alarm Set ALARM AUDIO to ON

All alarms

Set ANCHOR ALARM to

ON

Set ALARM AUDIO to ON

Set HONK OUTPUT to ALL

ALARMS

Anchor alarm Set

ON

ANCHOR ALARM to

Set HONK OUTPUT to

ANCHOR ALM

The 958’s standard alarm beep.

Alarm icons flash; the 958 simultaneously emits an output sound for half a second, followed by silence for half a second until the alarm is manually cleared.

The alarm icon flashes, and the alarm beeps (if the alarm audio is on), then after 10 seconds the honk sequence starts.


Understanding alarms. NORTHSTAR 958

Understanding alarms

Understanding alarm icons

Figure 8: Alarm icons

Displaying alarm messages

New alarm messages

Recent alarm messages

Clearing alarms

Table 6: 958 alarms

Table 6: 958 alarms (continued)

Table 6: 958 alarms (continued)

Table 6: 958 alarms (continued)

Table 6: 958 alarms (continued)

Table 6: 958 alarms (continued)

Table 6: 958 alarms (continued)

Changing alarm settings

.

Alarm audio

Anchor alarm

Cross-track alarm

Arrive radius

DGPS alarm

Setting alarms to honk

Honking for all alarms

Table 7: Beep and honk settings for all alarms

Related manuals

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Understanding alarms. NORTHSTAR 958