Northstar 941X User Manual

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Page 1

Northstar 941X

Refe rence Manual

SOFTWARE VERSION 2.05

30 SUDBURY ROAD

ACTON, MASSACHUSETTS 01720

(508) 897-6600

Page 2

Page 3

WARRANTY

Northstar Technologies, a Divisi on of CMC E lectr onics, Inc., wa rr ant ees it s pr oducts to be free from defects in material and workmanship for a period of two (2) years from the date of shipment to an authorized dealer. This warranty applies to the original purchaser or subsequent owner.

This warranty covers repair and/or replacement, at our option, of any part or parts found to be defective, provided such defects in our opinion are due to faulty material or workmanship and are not caused by tampering, abuse, or normal wear.

All warranties are F.O.B.: Northstar Technologies

30 Sudbury Road Acton, Massachusetts 01720

This warranty applies only to products in normal use. It does not apply to units or circuit boards defective due to improper installation, physical damage, tampering, lightning or other electrical discharge, receivers or ma inframes subjected to fresh water or saltwater immersion*, units with altered serial numbers, or units repaired by unauthorized persons or in violation of Northstar service procedures.

The foregoing are the only warranties expressed or implied. No other warranty exists.

Northstar assumes no responsibility for any conseq uential losses or damages of any nature with respect to any products or services sold, rendered, or delivered.

Certain Northstar control heads are warranty protected against damage due to

water leakage, provided the head has not been tampered with.

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IMPORTANT NOTICE

Although Northstar products are designed to be very useful navigation tools, they are not substitutes for good seamanship. T he prudent navigator should never rely on any single device as the sole source of navigation guidance. Exercise caution and good judgment whenever underway.

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1 2

ONTENTS

ONTENTSONTENTS

The Northstar 941X

The Northstar 941XThe Northstar 941X

Introduction ................................................................. 2

Upon First Start-up ......................................................2

Using This Manual........................................................3

941X Features...............................................................4

941X Functions............................................................. 5

Comparing GPS and Loran .......................................... 5

Mounting Basics ...........................................................9

Special Functions..........................................................9

The Display Screen.....................................................10

Interfacing Capability..................................................11

Using the Controls

Using the ControlsUsing the Controls

POWER Key................................................................ 14

CONTRAST Key.......................................................... 14

SAVE/MOB Key...........................................................15

Function Keys.............................................................16

Menu Keys....................................................................17

Cursor Keys..................................................................17

Keypad .........................................................................17

Special Display Windows ........................................... 18

Basic Navigation

Basic NavigationBasic Navigation

Displaying Position, Heading & Speed ......................22

Position Plotter...........................................................22

Using GPS...................................................................25

Using DGPS ................................................................26

Using Loran ................................................................30

Using Phantom Loran ................................................32

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Creating Waypoints and

Creating Waypoints and Creating Waypoints and

Routes

RoutesRoutes

Entering Data..............................................................36

Creating Waypoints....................................................37

Avoidance Areas .........................................................39

Waypoint Lists............................................................ 41

Coordinate Options ....................................................42

Updating Waypoint Coordinates ...............................42

Editing Waypoints......................................................43

Transferring Waypoints to a PC.................................44

Creating Routes ..........................................................44

Saving a Route ............................................................47

Changing a Route........................................................50

Waypoint & Route Navig

Waypoint & Route Navigaaaation

Waypoint & Route NavigWaypoint & Route Navig

Quick-Start Waypoint.................................................54

Navigating to Waypoints............................................ 55

Navigating Along Routes............................................59

Restarting the Course Line......................................... 61

tion

tiontion

The NAV LOG Function

The NAV LOG FunctionThe NAV LOG Function

What NAVLOG Does ..................................................64

Logging Your Trip.......................................................65

Changing Your Trip ....................................................65

Adding Waypoints to the Trip....................................66

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7 8

Other Special Functions

Other Special FunctionsOther Special Functions

Alarms.........................................................................68

Screen Backlighting.....................................................71

TideTrack™..................................................................71

Internal Differential Beacon Receiver ....................... 74

Customizing the 941X

Customizing the 941XCustomizing the 941X

Time of Day.................................................................78

Display Options ..........................................................78

Navigation Options.....................................................82

Receiver Options.........................................................87

Port Setup Options .....................................................90

Service Options........................................................... 91

Geodetic Datum..........................................................94

Installation and Interfacing

Installation and InterfacingInstallation and Interfacing

Mounting the 941X...................................................100

Wiring the 941X System........................................... 102

Antenna Location .....................................................104

DGPS Antenna Coupler (ACU).................................108

Interfacing the 941X..................................................112

Programming the Output Ports ................................115

Appendix

Appendix (Specifications) ........................................129

AppendixAppendix Glossary

Glossary..................................................................... 135

GlossaryGlossary Index

Index .........................................................................138

IndexIndex

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Figures

FiguresFigures

Tables

TablesTables

IGURE

F F F F F F F F F F F F F

T T T T T T T T T

1—MAX. P

IGURE

2—Y

IGURE

3—R

IGURE

4—941X GPS-O

IGURE

5—941X C

IGURE

6—S

IGURE

7—F

IGURE

8—C

IGURE

9—ACU A

IGURE

10—PL 259 (UHF) C

IGURE

11—I

IGURE

12—200 PPNM O

IGURE

13—941X D

ABLE

1—D

ABLE

2—I

ABLE

3—P

ABLE

4—NMEA 0183 S

ABLE

5—C

ABLE

6—C

ABLE

7—N

ABLE

8—Y

ABLE

9—C

OSITION VARIANCES WITH UNCORRECTED OKE MOUNT DRILLING DIMENSIONS EAR CONNECTORS

OMBO

TRIPPING THE COAX CABLE JACKET LARED CABLE BRAID

OMPLETED

NTERFACE CONNECTOR (MATING SIDE

ATUM LIST

NTERFACE CONNECTOR PINS

ORT SETUP OPTIONS

ONNECTION TO NORTHSTAR ONNECTION TO NORTHSTAR ORTHSTAR EOMAN ELECTRONIC PLOTTER SETUP WITH ONNECTING TO EXTERNAL

BNC C

SSEMBLY

IMENSIONS

.....................................................................97

800 S

......................................................103

NLY ANTENNA

GPS/DGPS A

(AN145 & AN150)..........105

NTENNA

..................................................108

ONNECTOR

...........................................................110

ONNECTOR

UTPUT BLOCK DIAGRAM

........................................111

......................................................132

........................................114

.....................................................116

ENTENCE IDENTIFIERS

800 P 800 P

ERIES OUTPUT PORT SETUP

NS B

...........................102

(AN190).............105

............................107

....................................108

)...................... 113

........................115

.............................120

ORT

A.....................123

ORT

B..................... 123

EACON RECEIVER

GPS....8

...............123

941X.......124

......125

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Introducing the Northstar 941X

Introduction 2

Upon First Start-up 2

Using This Manual 3

Features 4

Functions 5

Comparing GPS and Loran 5

Mounting 9

Special Functions 9

The Display Screen 10

Interfacing Capability 11

his section introduces you to the Northstar 941X navigator, outlining its various operational functions, in-

stallation configurations, and specifications. Use this section to get a quick overview of what the 941X is

all about, and how you can use it to your best advantage.

Rev. D 1 — Introduction

1 — Introduction Page 1

1 — Introduction1 — Introduction

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Introduction

HE NORTHSTAR 941X combines 12-channel GPS navigation with

Differential GPS capability, a high-definition display, loran compatibility, built-in tide data up to the year 2010, and many other navigation features.

For the ultimate in GPS accuracy, the 941X may be purchased as the 941XD, featuring an internal DGPS (Differential GPS) receiver. This advanced system gives you even greater accuracy by accepting Differential GPS signal “corrections” from shore-based transmitters (called “beacons”), and using them to display position fixes as accurate as 2-5 meters. You can also connect your 941X to any external source of DGPS corrections meeting the SC-104 standard (such as the Northstar 8800 DGPS Sensor).

Upon First

Start-up

When you turn your 941X on for the very first time, you may be greeted with a flashing exclamation poin t symbol in the lower right portion of the

GPS POSITION

the status box at the top. The flashing exclamation point simply means that an alarm message is present and waiting for your acknowledgment.

To see the message, press the

BACKLIGHT

screen, and the word

screen will be displayed.

ACQUIRE

STAR

key once. The

SKY SEARCH

ALARMS AND

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The alarm message date, are shown in the upper right corner of the box indicates that this is a previously unacknowledged message.

This sequence is a normal part of powering-up the 941X for the first time, as it notifies you that it is in the process of acquiring satellite information necessary for navigation. It normally takes only two to five minutes to acquire this data, after which the 941X is ready to navigate. (This alarm condition usually occurs in units sh ipped to customers located more than several hundred miles from the Northstar factory, and only the first time the 941X is turned on after being installed.)

NO GPS POSITION FIX

RECEN T ALARM S

box. The word

, along with its time and

NEW

in the

Using This

Manual

Press the acknowledge and clear the message. Press the left of the screen to return to the main is now ready to navigate. (For more on alarms, see page 68. If you wish to proceed directly to navigating with the 941X, skip to page 22.)

Your 941X was designed to be an easy-to-use, full-function GPS navigator, understandable in the information it displays and dependable in its performance. This Reference Manual is intended to complement that ease of use by illustrating and describing th e 941X’s various functions in a format helpful to quick learnin g and safe operation.

The sections in this manual are grouped by relat ed functions, beginning with an overview of basic control panel layout and function commands, and gradually progressing to more advanced waypoint and route navigation operations. Sample screen images are used throughout to help illustrate what the 941X displa y screen looks like for the function being described.

The “helpful hand” (pictured at left) is a convenient shortcut that leads you directly to step-by-step instructions. You can also use it as a quickreference for locating less-frequently-used operations.

CLEAR ALARM

menu key to the right of the display screen to

POSITION

GPS POSITION

key below the

screen. The 941X

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Features

Upon using the 941X, you’ll see that you can actually learn to operate the system’s various features without consta nt referral to th is manual. After you’ve read through it once, you won't have to refer to it very often again .

Since the 941X anticipates your most frequent requests for navigation information, accessing most functions req uires only one or two button pushes. By minimizing the attention needed to navigate, you can now devote more time to other aspects of your trip.

GPS features

navigation

features

waypoints and

routes

• accurate, worldwide position data in any weather, 24 hours a day

• optional internal DGPS (Differential GPS) Beacon Receiver for

accuracy as good as 2-5 meters

• fast signal acquisition

• fast-reacting, accurate speed and course

• lat/lon display

• built-in plotter shows:

1) your position relative to nearby waypoints;

2) your rece nt track line;

3) your intended course line; and

4) avoidance areas,

all against a latitude/longitude grid.

• tide prediction software integrated with navigation display (at

any NOAA tide station; for today or any other date.)

• stores up to 1,000 waypoints and 500 routes

• displays waypoints:

1) in alphabetical order

2) in order of distance from your present position

3) saved with the

4) stored as avoidance points

• plots position of:

1) nearby waypoints

2) routes

3) avoidance areas

SAVE

button

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Functions

Five keys on the 941X instantly select the most commonly used functions, as described below:

POSITION

Speed- and Course-Over-Ground, and Time and Date are also displayed. An alternate position screen plots your position graphically, along with any nearby waypoints and your track history.

STEER

waypoint. It also displays your Cross Track Error, Estimated time to waypoint, Estimated Time of Arrival, Course Over Ground, Speed Over Ground, Speed of Advance, etc.

( and accesses setup functions for customizing the operation and displays of your 941X, including screen brightness.

WAYPTS/ROUTES

navigation.

NAV LOG

trip) and lets you modify it.

displays position coordinates as

1) GPS lat/lon coor dinates

2) loran TDs, if you have a loran receiver interfaced to the unit

3) or calculated “Phantom Loran” TDs if you don't.

shows how to steer precisely along a course line to your current

STAR

) (The

key) displays alarm conditions and tide information,

lets you enter or access waypoints and routes for

displays the progress of your current navigation plan (toda y’s

In addition to these function keys, the your position as a waypoint, and provides a Man Overboard function for returning to the saved point.

MENU KEYS

Five tween specific choices displayed on the screen.

Comparing GPS

and Loran

The nation’s GPS system has received much publicity, often descri bed as providing the ultimate in navigation accuracy for all applications. Its major advantage over all other commercially-available navigation systems, including loran, is its all-weather, worldwide availability and

solute accuracy

device to determine your actual latitude and longitude coordinates on the surface of the earth, as compared to position information determined

Rev. D 1 — Introduction

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on the right edge of the display are used to select be-

. (

Absolute accuracy

SAVE/MOB

key instantly saves

ab-

refers to the ability of a navigation

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from a chart or other r eference. to return to a position whose coordinates you have previously recorded with the same equipment.)

Developed by the United States Department of Defense (DOD) the GPS system of 21 active satellites (with 3 additional spar es) literally encircles the earth with naviga tion information. GPS is offered in two forms: for military users and for civil users.

Repeatable accuracy

refers to the ability

selective

availability

GPS and DGPS

With GPS available to virtually anyone around the world, the DOD wanted to avoid the possibility that its precision could be used by hostile forces as a source of accurate targeting data against U.S. interests. To guard against such actions, they introduced intentional errors into the GPS signals that only U.S. forces could bypass. Called

(or SA), it involves a complex formula of data encryption that can

ability

abilityability

be turned on or off without the end-user ever knowing for sure whether it is in effect or not. DOD’s stated position is that SA will remain in effect indefinitely.

Selective Availability effectively reduces GPS’s absolute and repeatable accuracy from 30 meters (roughly 100 feet) 95 % of the time, to 100 meters (330 feet) 95% of the time. This means that, with SA, you can expect to be within 300 feet of your intended position 95% of the time, and beyond that area approximately 5% of the time. At first, this was accepted by most end-users as an inevitable part of GPS, a tradeoff against its global availability. But it didn’t meet the Coast Guard’s requirement of 820 meter accuracy for navigating harbors. It was then that a system of

differential corrections

them to effectively circumvent SA’s built-in errors.

was developed by the Coast Guard that enabled

Selective Avai

Selective Availlll----

Selective AvaiSelective Avai

These differential corrections are generated by fixed “refer ence stations” and broadcast by marine radiobeacons over a relatively limited area— usually a maximum broadcast radius of 250 miles—to Differentialcapable GPS (DGPS) receivers. The precise geographic location of the reference station is used to calculate corrections based on the GPS data received from the satellites, and the corrections are then broadcast to DGPS receivers. The receivers then convert this data into extremely precise position, heading and speed information. (Referred to as

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“beacons,” the transmitters are being situated at various locations along the U.S. coastline and Great Lakes, most of which are former marine radiobeacon sites.)

With DGPS, navigators are guar anteed position accur acy on the or der of

2-5 meters

much better). Lat/lon positions displayed to thousandths of minutes (roughly 6 feet) are common with DGPS. When using a radar or electronic plotter, DGPS corrections improve the steadiness of your displayed plot line dramatically.

In addition to accurate positioning information, DGPS provides critical “integrity monitoring” of the received GPS signals, enabling the user to be notified in seconds (as opposed to hours, with uncorrected GPS) that an anomaly has been detected in a transmitted satellite signal. The integrity monitor instructs the DGPS receiver not to use data from the satellite in question.

50% of the time, and to 10 meters 95% of the time (usually,

loran

Loran, on the other hand, can still outperform non-differential GPS— when SA is in effect—in weather and characterized by a relatively limited range (when compared to GPS), it’s a dependable system familiar to thousands of boat owners.

Since the 1970’s, LORAN users have relied upon that system’s ability to repeatedly get them back to a previously-saved location with extreme accuracy. Fishermen especially appreciated this capability because each subsequent visit to a lobster trap or buoy was virtually “on the mark,” saving them valuable time and money. Loran’s superior to anything else commercially-available at the time.

In very good coverage areas, loran can typically get you to within 50 feet (or roughly 14 meters) of your previously-visited target. On the other hand, at its very best, uncorrected GPS with SA enabled will get you to within

300 feet

uncorrected GPS—with variations of up to 300 feet in displayed position—wouldn’t be much help in getting you through a narrow channel. Since most loran chains were configured for optimum coastline navigation, it’s easy to see why loran’s masters and fishermen well for the last 25 years.

(100 meters) of your intended destination. Obviously,

repeatable accuracy

repeatable

. Though susceptible to

repeatable

accuracy has served harbor-

accuracy was

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Loran, however, isn’t as proficient as GPS in

absolute accuracy

, or visiting a spot for the first time. Since it transmits at a relatively low frequency (100 kiloHertz—similar to that on your AM radio), your ability to get an accurate position “fix” is directly related to: 1) your distance from the loran transmitters, and 2) the weather between you and the transmitters. It’s in these two areas that GPS consistently excels when it comes to

absolute

accuracy.

Even with SA, GPS provides an

absolute

accuracy of around 300 feet nearly everywhere in the world, under virtually any conditions. With a “constellation” of satellites orbiting the earth and transmitting their position data on an extremely high frequency (1.575 GigaHertz, or 1.5

cycles per second), GPS is impervious to weather and your location

lion

bil-

on the surface of the earth. You can receive position fix es at any time, anywhere, in any weather. This far surpasses the

absolute

accuracy that is achievable from a good loran receiver in a strong signal coverage area, in favorable weather conditions: usually 600 feet.

If you are accustomed to using your Northstar loran’s

repeatable

accuracy to return to within a boat length of a lobster trap or a buoy, time after time, you will not necessarily see this same performance with uncorrected GPS—you could be as much as 600 feet from your expected position. This will be especially apparent when using the 941X’s plotter screen (without DGPS), where you may see your boat’s plotted position appear to wander around within an area up to 600 feet in diameter (see Figure 1 below).

Position circle of 300-foot radius,

showing possible 600-foot error

between fixes.

ACTUAL

40°00.000 N

72°00.000 W

Figure 1—Max. Position Variances with Uncorrected GPS

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1 — Introduction1 — Introduction

300’

You could be

anywhere within

the circle, 95% of

the time.

Page 17

getting more

accuracy

If you need a higher level of accuracy than what basic GPS provides, there are two choices available to you:

Mounting

1. Use

2. Interface your

The 941X is designed to be yoke- or flush-mounted on your boat. The unit is waterproof and can be exposed directly to the weather. The GPS antenna should be mounted fairly low on th e vessel to minimize the effects of pitch and roll, and where it has a clear view of the entir e sky. Th e Beacon Receiver antenna (if installed) should be mounted fairly high, like a loran antenna. Refer to “Mount ing the 941X,” on page 100, for details.

Differential GPS

beacon receiver (or use an externally-located Northstar differential beacon receiver), or other source of differential corrections for your 941X. DGPS should provide better than 10-meter accuracy (repeatable and absolute) 95% of the time. See “Using GPS” on page 25 for more information.

the appropriate NMEA 0183 format output capability). You will then keep the “repeatable accuracy” of your loran, and add all of the navigation features of the 941X, including the excellent worldwide “absolute accuracy” of GPS. Refer to Table 2 on pa ge 114 for connector pin wiring guide.

by installing a Northstar internal differential

loran receiver

to your 941X (provided the loran has

Special

The following functions are unique to the 941X; you may want to read about them in detail before using them.

Functions

loran TDs

Rev. D 1 — Introduction

The 941X automatically converts GPS coordinates to loran TDs for those who have lists of fishing spots and other waypoints recorded as TDs. This feature is called Phantom Loran™. You can display your position as TDs or enter waypoints as TDs. The accuracy to be expected from this conversion is generally better than 500 to 1500 feet. You can also interface your existing loran receiver to the 941X and then display and navigate with

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real-time loran TDs. These features greatly ease the transition from using loran to using GPS. See page 30 for further details on using loran TDs.

plotter functions

TideTrack™

The Disp lay

Screen

The 941X’s plotter provides a picture of your position, and of what is around you. Nearby waypoints, avoidance areas, and a lat/lon grid may be displayed along with an image of your boat.

When you are using the plotter, the five menu keys below the display screen allow you to perform the following functions:

1) restart the desired track line to run directly from your position to the

waypoint, “zeroing” the cross-track error display

2) change the options available for the plotter

3) center the image of the boat on the screen

4) zoom in to show more detail

5) zoom out to show more area See page 22 for more information on using the plotter.

TideTrack displays a 24-hour tide graph for any of over 3,000 NOAA tide stations covering the entire U.S. coast, including Alaska and Hawaii, as well as much of the western Canadian coastline. Tides may be shown for today or any other day you ch oose. See page 71 for more information on using TideTrack.

The Liquid Crystal Display (LCD) and all controls are lighted for nighttime use. The display is easily readable under all conditions, from full sunlight to total darkness. Anti-ref lection treatment of the display and its window eliminates over 90% of the reflection and glare. Important data can be displayed using large numbers which can be seen from a distance.

To adjust the bright ness, press th e

DIM

and trolled by the

cleaning the

screen

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Use caution when cleaning the plastic window in front of the display screen. Although it is resistant to scratches, it can be damaged if you wipe dirt off with a dry cloth. Always use a damp cloth when wiping t he window. Use a small amount of window cleaner or alcohol to dissolve

menu keys to set the desired illumination. Contrast is con-

ARROW

1 — Introduction Rev. D

1 — Introduction1 — Introduction

key to the left of the screen.

STAR

key (

) and use the

BRIGHT

Page 19

any oil or grease on the screen. Whenever possible, avoid touching the window with your fingers, as natural oils from your hand will temporarily degrade the characteristics of the window and cause your finger prints to appear as bright reflections. These will disapp ear when the screen is cleaned as described above.

CLEANING HINT

CLEANING HINT Pre-packaged moist towellettes (especially those containing a small amount of alcohol) are excellent for cleaning t he display window. You might wish to keep a supply on hand to wipe off fingerprints and other smudges.

CLEANING HINTCLEANING HINT

Interfacing

Capability

The 941X contains two independent output ports for driving NMEAcompatible devices, two input ports for accepting data from other NMEA devices, and an auxiliary port reserved for future use. It also features an RS-232 port for input or output of SC-104 DGPS corrections, and waypoint/route or software program loading from a PC. The 941X can be interfaced to a wide variety of devices, including autopilots, plotters, radars, etc. Refer to “Interfacing the 941X,” beginning on page 112, for more information.

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Using the Controls

POWER Key 14 CONTRAST Key 14 SAVE/MOB Key 15

Function Keys 16

Menu Keys 17

Cursor Keys 17

Keypad 17

Special Display Windows 18

HIS SECTION describes each of the Northstar 941X's controls. Use this section for learning what each con-

trol does and for an overview of usin g its various functions.

Rev. D 2 — Using the Controls

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2 — Using the Controls2 — Using the Controls

Page 22

HE MAJOR FUNCTIONS of each of the 941X's controls are de-

scribed in this section.

POWER Key

Press the special startup screen that includes an owner-identification message which you may customize to aid in theft-prevention. Next, the 941X displays the results of the internal self-tests that are automatically run each time the unit is turned on. Finally, navigation data is displayed.

If any of the six major components of the 941X fails the self-test, the notification acknowledge it with the press of any function key (located below the display screen). Return the 941X to the factory for service.

POWER

SYSTEM TEST: FAILED

switch briefly to turn on the 941X. The unit displays a

will remain on the screen until you

To turn the 941X off, press the one full second until the unit turns off.

CONTRAST Key

Page 14 2 — Using the Controls

Liquid Crystal Display (LCD) screens require a contrast adjustment to compensate for different viewing angles, temperature conditions, etc. The 941X's contrast control allows you to adjust its display screen to give the best picture for your current condit ions. Pressing the upper contrast arrow darkens the screen, and pressing the lower arrow lightens it. Adjust the screen for the best contrast as seen from your normal operating location.

2 — Using the Controls Rev. D

2 — Using the Controls2 — Using the Controls

POWER

switch and hold it in for at least

Page 23

SAVE/MOB Key

SAVE/MOB

The It does this in either of two ways, depending on whether you press the key briefly, or press and hold it.

key is used to save your current position as a waypoint.

saving a

waypoint

Man Overboard

feature

Press the new waypoint will automatically be given a name, such as –S002–, where the letter S indicates a saved waypoint, and the 3-digit number increases by one every time you save a waypoint.

The waypoint’s 3-digit number will “wrap around,” or revert, to –S001– when the 941X has reached the limit you set using the

WPT #

Press and hold the Overboard” (MOB) mode. The 941X saves your position and displays it in the plotter screen as an “X.” The plotter screen is locked on the display, showing your position and the MOB location. The MOB location immediately becomes your current waypoint, with new bearing and distance information displayed on the right-hand side of the screen.

SAVE/MOB

function under

SAVE/MOB

button briefly to simply stor e your position. Th is

MAX SAVED

DISPLAY OPTIONS

button for three seconds to enter “Man

(see page 80).

INVOKING MOB WHILE USING AN AUTOPILOT Some autopilots will attempt to steer your boat according to any bearing changes output by the 941X, regardless of the severity of the change. Others automatically disengage when a severe or abrupt turn is required. Please refer to your autopilot manual for information regarding this procedure.

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Page 24

To leave MOB mode and return to normal navigation, press for at least three seconds.

SAVE/MOB

Function Keys

POSITION key

“Where am I?

STEER k ey

“How do I

get to my

waypoint?”

The five function keys located below th e display screen control wh at the 941X is doing. Any function key may be pressed at any time to display the information you need to see.

POSITION

The plotter screen to show your position graphically, relative to nearby waypoints and your track history. Course-Over-Ground and Speed-OverGround are displayed at the bottom of the screens.

Position coordinates may be shown as any of the following:

1) Lat/lon from GPS

2) Lat/lon from an external loran receiver

3) loran TDs from an external loran receiver

4) Phantom Loran TDs which the 941X calculates fr om its GPS coordinates

STEER

The picture of your position relative to the course line is displayed, along with all the numeric information you need to steer directly to your waypoint. Two versions of the steer display are avai lable. Press the version you were last using. Press it again to see the other version.

key displays your position coordinates, or displays a

key shows how to steer to a waypoint you h ave desi gnat ed. A

STEER

once to see

STAR

STAR key

WAYPTS and

ROUTES key

“Where do I

want to go?”

Page 16 2 — Using the Controls

The alarms and messages the 941X has waiting for you. The second press displays information about tides for your choice of over 3000 NOAA tide stations. The third press displays the time of day, and the time of today’s sunrise and sunset. The fourth press displa ys a menu of setup and customization functions used whenever you wish to change the way the 941X works for you.

The access a library of waypoints and routes that you have entered previously, or specify where you want to navigate to.

See Sections 4 and 5 for waypoin t and route information.

key (

WAYPTS/ROUTES

2 — Using the Controls Rev. D

2 — Using the Controls2 — Using the Controls

) has several functions. The first pr ess displays any

key allows you to enter waypoints and routes,

Page 25

NAV LOG key

“How am I

doing?”

NAV LOG

The you to change those ahead of you. See “What NAV LOG Does,” on p age 64, for more information.

key displays the waypoints you have passed, and allows

Menu Keys

Cursor Keys

Keypad

entering

numbers

The five round used for different purposes depending on what function is currently being used or displayed. The function of each key is labeled on th e screen, and pressing the key performs the displayed function.

A large cursor pad in the upper right corner of the 941X allows you to move the flashing cursor on the display screen to the data you want to display or change. For example, when entering data (such as a waypoint’s name or coordinates) press the down arrow to move the cursor downwards to a particular field of data and press the right arrow key to move the cursor to a particular character in that fiel d.

The 12-button alphanumeric keypad is used for entering numbers, letters or special characters for waypoint coordinates, names, etc.

When the 941X is expecting you to enter numbers only, such as for waypoint coordinates, the keypad keys enter one digit, 0-9, with each keypress. The flashing cursor moves automatically to the next digit position.

keys on the right side of the display screen are

For entries such as latitude and longitude—where the digits must be entered into specific characte r positions—the cursor starts on the left side of the field and characters are entered left to right into their correct positions.

For other numeric entries such as dist ances—wh ere a number of var ia ble length may be entered—the digits are entered calculator-style from the

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Page 26

right side of the field. If you make a mistake, you can press clear the entire number and re-enter it, or you can press the left-arr ow cursor key to reenter particular digits, one at a time.

CLEAR

entering letters

CLEAR and

ENTER keys

When the 941X is expecting letters to be entered, such as waypoint names and descriptions, the operation is slightly different. Each key is labeled with three letters (or other special characters) and a digit.

For example, the upper left key is labeled with the letters A, B, C and the digit 1. Pressing the key one time displays the letter A. Press the key again to display the second letter, B. Pressing a third and fourth time displays the letter C and the digit 1, respectively. A fifth press br ings you back to the letter A again.

To enter a character, first find the key containing the character, and press that key one to four times to display the desired character. Finally, move the cursor to the next character position by pressing the right arrow symbol on the cursor key.

The keypad also contains ing data that has been typed on the keypad. Pressing the always the last step when entering or changing data, or acknowledging an action. The

ENTER

you changed it.

CLEAR

, and sets the field to all blanks or restores it to its value before

CLEAR

key removes any data you typed before you press

and

ENTER

keys for erasing or enter-

ENTER

key is

Special Display

Windows

alarm messages

Page 18 2 — Using the Controls

Occasionally, the 941X needs to inform you of someth ing or ask permission to do something. When this happens, a special information or question window appears on the display. The window contains an

exclamation point (“ and a message for you to read.

Alarm messages contain information you should read right away. Alarms are communicated by the flashing exclamation symbol in the bottomright portion of the display.

Press the

BACKLIGHT

edge and clear the message.

STAR

2 — Using the Controls Rev. D

2 — Using the Controls2 — Using the Controls

!!!!

”), an “

key once to show the alarm condition on the

screen. Press the

INFO

” label, or a large question m ark (“

CLEAR ALARM

menu key to acknowl-

”),

ALARMS &

Page 27

information

windows

Information windows

control functions. They give you extra details pertaining to wha t is about to happen, or let you acknowledge a command. Information windows always appear with the word “

are displayed while you are entering data or using

”

INFO

in a small box.

question windows

Rev. D 2 — Using the Controls

Question windows

what you want to do. A question mark will always appear in this type of window.

You must respond to any question window by pressing “YES,” or keys, are inactive when a question window is displayed.

CLEAR

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2 — Using the Controls2 — Using the Controls

appear when the 941X needs to know more about

to answer “NO.” All other keys, including the function

ENTER

to answer

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Basic Navigation

Displaying Position, Heading & Speed 22

Position Plotter 22

Using GPS 25

Using Loran 30

Using Phantom Loran 32

HIS SECTION describes the most basic—yet important—navigation function available in the Northstar

941X: determining your position. Position coordinates may be determined from the GPS sat-

ellite system, or you may display loran coordinates if you have connected a loran receiver.

For those who no longer have a loran r eceiver, but wish to view their posit ion in loran TDs , the 941 X can conver t GPS coordinates into Phantom Loran coordinates.

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Displaying

Position,

Heading &

Speed

O DISPLAY the coordinates of your current position, simply press

the button marked position coordinates at the top, and your Course-Over-Ground (COG) and Speed-Over-Ground (SOG) at the bottom. (If you see the screen displayed instead of your position coordinates, just press the

POSITION

GPS position coordinates are displayed as latitude and longitude. You may choose to display loran coordinates instead, as described below. (Loran coordinates may be obtained fr om a loran receiver connected to the 941X, or may be calculated by th e 941X from the GPS posit ion coordinates.)

button again).

POSITION

. A screen is displayed showing your

PLOT

Positio n Plo tter

Page 22 3 — Basic Navigation

The position plotter screen is a “ nort h-up ” di spla y, a nd pr ovid es an over all view of the surrounding area and all nearby waypoints. Press the

POSITION

route (if any), your track history, and any nearby waypoints and avoidance points.

A maximum of 30 local waypoints can be displayed on the plotter screen at one time.

key to show your position plotted relative to your current

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Page 31

The image of your boat displayed on the screen points in the direction of your Course-Over-Ground. Remember, this direction may be different from your heading. The boat image shows your actual direction of travel over the bottom, not the direction your boat is headed. If your boat is not moving, the Course-Over-Ground cannot be determined by the 941X, and the direction of the boat on the screen has no meaning.

Avoidance areas (waypoints for which a warning radius has been sp ecified) are shown as a circle surrounding the waypoint.

Your present Speed-Over-Ground (SOG) and Course-Over-Ground (COG) are displayed at the bottom of the screen, along with the chart scale. The chart scale is the distance from the top edge to the bottom edge of the plot.

zooming

centering the

plot

course restart

The plotter screen can be used to steer by when t he object ive is simply to get to the waypoint without needing to remain precisely on the designated course line.

Press the the center of the screen. Press the see more area. Each press of the IN or doubles the chart scale, respectively.

The maximum zoom-in screen displays an area that is approximately ¼mile from the top edge to the bottom, while maximum zoom-out shows you an area that is up to 128 miles, top to bottom.

Press the that your boat is at the center of the screen.

If you wander off your intended course line, and you want to navigate directly to the waypoint rather than returning to the original course line, press the computed and displayed, running from your present position to the next waypoint.

ZOOM IN

CENTER

RESTART

menu key to zoom in for a closer look at the a rea in

menu key at any time to move the plotted area so

menu key, then

NOTE:

ZOOM OUT

OUT

ENTER

menu key to zoom out to

key approximately halves or

. A new course line will be

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Page 32

plotter options

To set up the parameters for the display of data on the plotter screen, press the

The plotter control menu allows you to change the following items:

OPTIONS

• The plotter scale at and above which waypoint names will not be

displayed on the plotter screen

• Whether local waypoints are displayed on the screen

• How often your position is recorded on the screen

• Whether your track history is displayed on the screen

• Whether a lat/lon grid is displayed on the screen

menu key. The following screen is displayed:

Page 24 3 — Basic Navigation

To change any one of these, use the up and down cursor keys to move the arrow to the item you want to change, and press th e This will cause a large cursor to flash on the field, indicating you should use the up and down cursor keys to select the option you want. Press

ENTER

The 941X can store up to 900 points in its track, so the maximum length of the track depends on how often points are stored.

You may choose to store track points every second, with a maximum length of 15 minutes, or every two minutes for a maximum length of 30 hours, or a number of settings in between.

when done, or

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CLEAR

EDIT

menu key.

to restore the field to its original value.

Page 33

You may also choose to freeze the track, so that no more points will be stored and the track will remain unchang ed.

Using GPS

lat/lon

coordinates

Pressing the on the screen.

Press the

Your 941X contains an internal GPS receiver which is used as the primary source of position data.

GPS data is displayed directly on the

The GPS position screen displays your latitude and longitude in large digits near the top of the screen. If GPS da ta is not ava ilable, dashes a re displayed in place of the numbers.

CLEAR TRACK

RETURN

menu key to go back to the plotter screen.

menu key clears the track history displayed

GPS POSITION

screen.

You can display lat/lon as either degrees, minutes and seconds, or as degrees, minutes and thousandths of minutes. See “Display Options,” on page 78, to select one or the other.

time of day

speed and

course

Rev. D 3 — Basic Navigation

The time of day and today’s day and date (obtained from the GPS satellites) are displayed at the bottom of the screen.

Near the bottom of the screen, your Speed-Over-Ground and CourseOver-Ground are displayed in large digits.

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Page 34

The 941X’s speed and course rea dings are t he result of instan taneous measurements derived from satellite signals. GPS speed is updated every second. However, you may average these readings by changing the “GPS speed averaging” value (see page 87).

NOTE

datum

status summary

In the center of the screen, the name of the datum currently in use is displayed. The datum describes the reference of the chart you are currently using (the reference datum used is indicated on each chart). Applying the datum corrects for any position differences between your chart and the GPS coordinate system. See “Geodetic Datum,” on page 94, for more information on selecting the datum for your area.

When using differential GPS (DGPS) as your navigation source, your position, as displayed by the 941X, may actually exceed the accuracy of some charts.

NOTE

At the top center of the position screen is a brief status summary of the GPS receiver. The following table shows the various st atus messages the 941X may display, along with their meanings.

Message Meaning

ACQUIRE SKY SEARCH TRACKING 2D NAV 3D NAV POOR FIX COMM FAIL

trying to acquire satellites searching for satellites with no previous information satellites have been acquired; almost ready to navigate navigating with 3 satellites in 2-D mode navigating with 4 or more satellites in 3-D mode tracking satellites with poor geom etry/accuracy communication link to GPS sensor has failed—unit

needs repair

Using DGPS

In the upper right corner of the that shows whether Differential GPS (DGPS) corrections are in use. If your installation includes an optional Northstar internal differential GPS receiver, or other external source of differential corrections, navigational accuracy will be significantly improved when this indicator is present.

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GPS POSITION

screen is an indicator

Page 35

For further information on operating in DGPS mode, refer to “Internal Differential Beacon Receiver,” on page 74.

With DGPS active, you will often see position measurements accurate to about 2-5 meters, speed measurements accurate to about 0.1 knot, and Course-Over-Ground measurements accurate to about 0.5 degree. DGPS corrections remove the errors caused by Selective Availability (SA) and the atmosphere, and provide an accuracy exceeding that obtained by military users of the GPS system. If the DGPS indicator is displayed, you have this higher level of accuracy. For the

POSITION

and

STEERING

screens, the DGPS indicator is a large letter “D.” For the plotter screen, the DGPS indicator is the symbol

DGPS

satellite status

To display more information about signa ls received from the GPS satellites, press the

SATS

menu key on the GPS position screen. A screen is displayed showing the received Signal-to-Noise Ratio for each satellite, and a map indicating where the satellites are currently located in the sky (the 12-channel are identified by their

GPS SATS

PRN

U.S. government. The center of the satellite map represents the center of the sky, and the

outer (or last) ring is the hor izon. The view is looking down from above, with East to your right and West to your left.

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screen is shown on the next page). Satellites

number, a two-digit number assigned by the

Page 36

On five-channel 941Xs, the last bar at the bottom of the screen will sometimes “jump” around once per second as the 941X receiver sequen ces among other satellites.

NOTE

The following GPS data is also displayed:

ACCURACY

ACCURACY: The estimated accuracy of the GPS system to be

ACCURACYACCURACY expected at the current time. Your position readings should be more accurate than this estimate 95% of the time.

HDOP

HDOP: This is a technical measure of the “quality” of your fix.

HDOPHDOP HDOP (Horizontal Dilution of Precision) ca n range from an idea l value of 1, up to 10 or more. Any value less than 2 indicates excellent performance. HDOP is calculated from the satellites’ current positions, and is not based on actual received signals. You will usually see an HDOP value displayed immediately after the unit is turned on, and before it is ready to navigate.

RETURN

DGPS

menu key to return to the previous screen.

menu key on the GPS position screen. A screen is

DGPS status

Press the

To display more information about DGPS corrections that are being received, press the displayed showing the DGPS beacon transmitter currently in use. The upper part of the screen shows the beac on’s name and position, the frequency of the transmitter, and the baud rate of the transmitted data.

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Page 37

The lower part of the screen shows three bar graphs:

1. SNR

SNR The Signal to Noise Ratio (SNR) is a good overall mea sure of

SNRSNR overall signal quality, and should be as high as possible. Values of 15 and higher are preferred, while anything below 10 could indicate poor reception.

2. SIGNAL

SIGNAL The actual strength of the received signal—should be as

SIGNALSIGNAL high as possible. Varies with distance from beacon transmitter.

3. NOISE

NOISE Noise level measures the “static” caused by lightning and

NOISENOISE other atmospheric effects, a nd should be low for best results. See “DGPS antenna mounting” on page 112, for further details.

NOISE LEVEL VALUE MEANING

200 or less excellent

1,000 – 3,000 typical at night

5,000 – 10,000 thunderstorm

At the bottom of the screen a summary of DGPS operation is displayed. You may see one of the following messages:

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Page 38

MESSAGE MEANING

OLD CORRECTIONS

NOT INSTALLED UNHEALTHY BEACON UNHEALTHY SATS

ACQUIRING SATS

DGPS IN USE/ OK

DGPS signal quality information for the 941X is available from the optional internal beacon receiver, or from an opti onal external Northstar beacon receiver. Other brands of beacon receivers may supply DGPS corrections but omit the additional signal information shown on the 941X’s screen.

No DGPS corrections have been received within the

RECEIVER OPTIONS

in ute), and the navigator has returned to nondifferential operation. See “GPS data timeout” on page 89 for details. A beacon receiver is not installed.

The beacon transmitter reports it has problems.

Data received from satellites cannot be relied upon.

1) The GPS receiver cannot operate in DGPS mode until it has received ephemeris data from the satellites; or 2) the receiver does not have a GPS fix yet. DGPS corrections are being received and used.

DGPS DATA TIM EO UT

(default is 1 min-

limit set

Using Loran

selecting loran

Press the

If you have a loran receiver connected to your 941X, you can navigate using loran coordinates as well as GP S. Just select lor an as t he source of

navigation data, as described below, and you’re on your way.

To display loran TD coordinates from a loran receiver interfaced to the 941X, first select loran as the navigation source, as described below.

1. Press the

2. Press the

3. Press the

RETURN

displayed.

SOURCE

menu key to return to the previous screen.

STAR

key until the

NAVIGATION OPTIONS

line will be designated by the cursor arrow.

EDIT

menu key. The cursor will begin flashing.

USER CU STOMIZATION

menu key. The

screen is

NAVIGATION

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Page 39

4. Press the up and down cursor arrow keys to display

LRN

as the position source. If you change your mind, press

to restore the original setting; otherwise, press

RETURN

menu key.

ENTER,

EXTERNAL

CLEAR

then the

loran TDs

The loran display screen looks like this:

Press the pair of TDs you wish to use, or the loran-derived latitude/longitude.

L/L TDS

In order to display loran position coordinates on the 941X from an externally-connected loran receiver, the loran must support the standard NMEA 018 3 “RMA” output data sentence structure. Without this output capability, the 941X will not receive position data from the loran. For best results, connect a Northstar 800 series loran to the 941X, using the 800’s “PRINTER 3” output format. See “connecting to a Northstar 800 series loran” on page 123.

menu key several times to select either the p arti cular

NOTE

loran GRI

loran warnings

Rev. D 3 — Basic Navigation

The four-digit loran Group Repetition Interval (GRI) is changed using

SET GRI

the this to correctly match the GRI being used by your loran receiver for the 941X to accurately convert the loran’s TDs to latitude/longitude position fixes.

Loran warning indicators obtained from any Northstar 800 series loran receiver are displayed to the right of each TD. These are:

menu key on the

3 — Basic Navigation Page 31

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LORAN POSITION

screen. You must set

Page 40

INDICATOR MEANING

SNR

BLNK

CYC

LOCK

Note: These indicators are available only from Northstar 800 lorans.

The “L/L” indicator to the left of a TD designates it as one of the two TDs that the loran receiver has chosen to use to calculate latitude and longitude.

The “F/L” indicator to the left of a TD indicates that it has been forced by the user to be used to calculate lat/lon.

Signal-to-Noise Ratio is low—use caution Coast Guard is transmitting a blink signal indicat-

ing a probable transmitter problem the receiver has detected a possible cycle slip the receiver has locked onto the loran track point. This is not a warning indicator but an indication of normal performance.

loran info

checking GPS

status

returning to GPS

navigation

Using Phantom

Loran

Phantom Loran

operation

To check the quality of signals being received by your loran, press the

LORAN INFO

nal-to-Noise Ratio for each loran transmitting station is displayed graphically. Press

To temporarily display GPS coordinates and signal status, press the

CHECK GPS

will display loran data the next time you return to the position screen.

To return to GPS signals for naviga tion, r ep eat th e step s sh own ab ove for selecting loran, except specify GPS instead of loran.

The 941X’s Phantom Loran feature is designed for th ose users who have compiled lists of fishing spots or oth er locations as loran TDs, and are now using the 941X as a GPS-only navigator. The 941X will mathematically convert GPS lat/lon coordinates to loran TDs, enabling y ou to display your position as TDs.

The 941X may be used to simulate full operation of a loran receiver. Position coordinates may be displayed as TDs, and all navigation functions may be used as if the unit were actually receiving loran signals. Remem

menu key from the

RETURN

menu key. The unit continues to navigate using loran, and

to go back to the loran position screen.

LORAN POSITION

screen. The Sig-

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Page 41

ber, however, that these calculated TDs will not match exactly the positions of previously recorded TD coordinates obtained directly from actual loran signals. In most areas, errors should not exceed 0.2 microsecond. However, larger errors are possible in areas for which the 941X does not contain accurate, factory-programmed ASF correction points.

selecting

Phantom Loran

TDs

To display Phantom Loran TDs as position coordinates, first select Phantom Loran as the position source, as described below.

1. Press the displayed.

2. Press the

GATION SOURCE

3. Press the

4. Press the up or down arrow keys to display position source.

5. Press

6. To view your position in Phantom Loran coordinates, press

POSITION

The Phantom Loran display screen looks like this:

STAR

key until the

NAVIGATION OPTIONS

line will be designated.

EDIT

menu key.

ENTER

, then the

USER CU STOMIZATION

menu key.

RETURN

menu key.

screen is

THE NAVI-

PHANTOM LRN

as the

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Page 42

choosing L/L or

TDs

Press the TDs you wish to use or to display GPS latitude/longitude.

L/L TDS

menu key several times to select the particular pair of

Phantom Loran

GRI

checking GPS

status

checking DGPS

status

DGPS

corrections

returning to GPS

navigation

Press the the displayed TDs. Press the up and down cursor keys to display the available GRIs one at a time. When the GRI is correct, press

Press the status, as described on page 27.

Press the beacon receiver, including SNR, SIGNAL and NOISE values (as previously described on page 29). Press the

The large letter displayed in the upper right corner of the display indicates differential GPS corrections are being received and used to improve the accuracy of the received data.

To return to GPS signals for naviga tion, r ep eat th e step s sh own ab ove for selecting loran, except specify

See “Navigating to Waypoints,” beginning on page 55, to learn how to navigate to loran, Phantom loran, or GPS coordinates.

SET GRI

SAT INFO

DGPS INFO

PHANTOM LORAN

menu key to change the GRI to be used in calculating

menu key to check on the received GPS satellite

ENTER

menu button to display the current status of the

RETURN

position screen.

GPS

instead of Phantom Loran.

when you wish to go back to

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Page 43

Creating Waypoints and

Routes

Entering Data 36

Creating Waypoints 37

Avoidance Areas 39

Waypoint Lists 41

Coordinate Options 42

Updating Waypoint Coordinates 42

Editing Waypoints 43

Transferring Waypoints to a PC 44

Creating Routes 44

Saving a Route 47

Changing a Route 50

In this section, we’ll learn how to create waypoints, use them to form routes, and change them as necessary.

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Page 44

Entering Data

Before we move on to the sections describing how to enter waypoints and routes into the 941X’s memory, let’s take a break and review the methods for entering data into the unit.

Some screens, such as coordinate entry screens, allow entry of numbers only. Others, such as waypoint names, allow entry of letters, d igits and punctuation characters.

A typical entry screen will have several items of data displayed. First, choose the item you wish to change by pressing the up or down cursor arrow key to move the flashing cursor to that item.

The flashing cursor indicates which character position will be written into. Use the left and right cursor arrows to move the flashing cursor to the next character you want to enter.

Use the up and down arrows to move to the next line you want to enter.

entering

numbers

entering letters

When the entire screen is correct, press th e accept the full screen of data and store it in memory.

To enter numbers, simply press the digits of the keypad. The flashing cursor automatically moves to the next character.

You can use the arrow keys to “back up” and correct any mistakes you might have made.

Many items, such as waypoint names, accept letters as well as numbers. Each key of the keypad is labeled with up to four characters. Find the key with the desired character, and press that key one or more times to display the character. When the char acter has been selected, use the right arrow cursor key to move the cursor to the next character position. Press

ENTER

Here are some of the things you can do with waypoints using your 941X:

when all the characters are correct.

1. Navigate to a point in one step (a “quick start” waypoint)

2. Enter waypoints into the 941X’s memory for later use

3. Navigate to these waypoints

ENTER

key. The 941X will

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Page 45

4. String these waypoints together to form routes

5. Follow these routes

6. Edit or erase waypoints or routes

7. Plot waypoints or routes

8. Transfer waypoints and routes from the 941X to a personal computer, and back again.

Creating

Waypoints

To enter waypoints, press the

WAYPT LI ST

to the following is displayed:

To store a waypoint permanently in the 941X's memory, first assign it a name. The name can be from 1 to 6 characters long, and it must differ by at least one character from any other waypoint name in the unit's memory.

Enter the desired waypoint name. If you wish, you may also enter up to 16 characters of descriptive information for the waypoint on the line below the name (the description is optional).

menu key and then the

WAYPTS/ROUTES

ADD

menu key. A screen similar

key. Press the

If the name you chose is already in use in t he unit’s m emory, a message is displayed, indicating you cannot use that name. You can either erase the old waypoint, i f it i s no longer n eeded, or choose a different name for the new waypoint. The name of the new waypoint need only be different from the existing waypoint by one character in order to be accepted as a valid name.

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Page 46

waypoint

coordinates

Waypoint coordinates can be entered as lat /lon coordinates, loran TDs, or as distance and bearing from your present locat ion or from any waypoint in the 941X’s memory.

To change the coordinate type from what is currently displayed, press

COORD TYPE

the Enter the waypoint coordinates as previously described on page 36. If

you make a mistake, press start over; otherwise, press

If you are entering coordinates as distance and bearing, the 941X normally asks for these coordinates relative to your current position, known

HERE

as “–

–.”

menu key until you see the option you want.

CLR

to erase any characters from the line and

ENTER

when the screen is correct.

To select an entirely different location from which distance and bearing are to be measured, such as an existing waypoint, p ress th e key. A waypoint list is displayed. You can press the

COORD OPTION

Use the up and down cursor arrow keys to point to the desired waypoint. Press the ous screen. If you wish instead to use your present position as the reference point, press the

POSITION

Page 38 4 — Creating Waypoints and Routes

ENTER

screen.

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menu keys to help select the waypoint.

key to designate this waypoint and return to the previ-

FROM ‘HERE’

FROM

NEXT LIST

menu key on the

‘FROM’

Page 47

avoidance area

If this new waypoint is to be used as the center of an ter the warning radius at the bottom of the screen in the box. If no radius is entered, the point will be treated as a regular waypoint, and not as an avoidance area.

avoidance area

WARN RADIUS

, en-

Avoidance

Areas

You may designate new or existing waypoints as avoidance ar eas. Avoidance areas are depicted on the around them. In addition, an alarm will be given both as an audio beep and a flashing exclamation point on the screen, if you should enter and avoidance area.

The 941X will display each avoidance area as a circle the size of the warning radius you entered. For new waypoints, enter a distance in the

WARN RADIUS

isting waypoints, use the point coordinate screen, then enter the warning radius. Be sure to include a little extra distance around the hazard so that you will have time to respond by turning or stopping after you hear the alarm.

box at the bottom of the

PLOT

screen as waypoints with circles

EDIT WAYPOINT

NEW WAY PT

function to access the way-

screen. For ex-

Rev. D 4 — Creating Waypoints and Routes

4 — Creating Waypo ints and Routes Page 39

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Page 48

As a precaution, once you have designated a waypoint as an avoidance area, the 941X does not allow you to navigate to it.

avoidance area

alarm

Once you have designated a waypoint as an avoidance area, the 941X will alert you upon penetration of that are a.

To set the audible avoidance area alert feature:

1. Press the screen.

2. Be sure that the cursor arrow is in front of the option.

3. Press the

4. Use the up/down cursor keys to toggle the setting ON or OFF.

5. Press changed.

(NOTE: If you do not want to be notified of any other navigational alarms, set the

DGPS

and enter an avoidance area.)

The 941X’s avoidance alarm is intended only as an extra added safety feature to help make you aware of possible hazards. It does not replace local knowledge, prop er us e of cha rt s, t he p erson on watch, or any other aspects of good seamanship that are required for safe navigation.

STAR

key once to display the

EDIT ALARM

ENTER

alarms to OFF. The audible alert will now only beep when you

to make your selection, or

ANCHOR DRAG, CROSS TRACK, ARRIVE RADIUS

menu key.

CAUTION:

ALARMS & BACKLIGH T

ALARM AUDIO

CLEAR

to leave it un-

Page 40 4 — Creating Waypoints and Routes

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Page 49

Waypoint Lists

Waypoints contained in your 941X can be displayed in any of four ways. Press the

WAYPTS/ROUTES

function key, then the

menu key to display waypoint lists. Use the

NEXT LIST

WAYPT LIST

menu key to se-

lect the list that is best for your current situation. Each press of the

NEXT LIST ALPHA, SAVED, AVOID

ALPHA

ALPHA list: all waypoints in alph

ALPHAALPHA

menu key displays a waypoint list in the following order:

LOCAL

and

list: all waypoints in alphaaaa----

list: all waypoints in alph list: all waypoints in alph

betical order

betical orderbetical order

, then starting again at

SAVED

SAVED list: all waypoints

list: all waypoints

SAVEDSAVED

list: all waypoints list: all waypoints

created via SAVE/MOB

created via SAVE/MOB key,

created via SAVE/MOBcreated via SAVE/MOB

with most r

with most reeeecent first.

with most rwith most r

ALPHA

cent first.

cent first.cent first.

key,

key, key,

AVOID

AVOID list: Avoidance waypoints within 100

list: Avoidance waypoints within 100

AVOIDAVOID

list: Avoidance waypoints within 100 list: Avoidance waypoints within 100

nm,

nm,nm,

nearest first

nearest firstnearest first

alpha list

Waypoints listed under the

ALPHA

displayed in alphabetical order. Waypoints with a digit as the first character appear near the beginning of the list. “Saved” waypoints appear near the end.

Rev. D 4 — Creating Waypoints and Routes

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LOCAL

LOCAL list: 30 closest waypoints within

list: 30 closest waypoints within

LOCAL LOCAL

list: 30 closest waypoints within list: 30 closest waypoints within

100 nm,

100 nm,100 nm,

nearest first

nearest firstnearest first

screen in the 941X’s memory are

Page 50

saved list

All saved waypoints (stored by pressing the having a name such as –S001–) are listed in order of the time at which they were saved, with the most recent first.

SAVE/MOB

button, and

avoid list

local list

Coordinate

Options

Up to 30 avoidance points within 100 nautical miles are listed in order of their distance from your position.

LOCAL

In the miles are listed in order of distance from your p osition. This list is particularly useful when you wish to deal with only the wa ypoints in your area. Even though you may have hundreds of waypoints stor ed, the local waypoints are very often the only ones you are interested in. You may find yourself using this list most of the time.

Whenever a waypoint list is displayed, you may display the waypoint’s coordinates on the right side of t he screen in any of t he following ways, by pressing the

1. latitude/longitude coordinates

2. coordinates originally used to save the waypoint (TDs, lat/lon)

3. distance and bearing from your position (this is often the most useful way, since it may be easier to visualize “3 miles north” than the digits of lat/lon coordinates).

The letter “S” to the right of the waypoint name indicates that the displayed coordinates were the ones used to store the waypoint (TDs vs. lat/lon).

list, up to 30 of the closest waypoint s within 100 nautic al

COORD OPTION

menu key:

Updating Waypoint

Coordinates

Page 42 4 — Creating Waypoints and Routes

Often a waypoint is taken from a chart by measuring the approximate coordinates with whatever accuracy is allowed by the chart. When you sail to the waypoint, you may fi nd its position is slightly different th an expected. The 941X has a special feature that allows you to easily recalibrate the waypoint by setting its coordinates to your precise position. You can also use this feature to convert approximate loran TD coordinates to precise GPS coordinates.

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Page 51

To update a waypoint’s coordinates, first sail to the spot where the waypoint will be located. Press menu key, to display a list of waypoints on the screen. Pr ess the

LIST

menu key, if necessary, to show the local waypoints (in order of distance from your position). Your wayp oint should be a t or near the top of this list. Use the up and down arrow keys to point to the desired waypoint. Press the key, and finally the

EDIT

ENTER

WAYPTS/ROUTES

menu key, and then the

key.

, then the

UPDATE COORD

WAYPT LI ST

Editing

Waypoints

The new coordinates are recorded at the instant you press the

COORD

To change any information about a waypoint you have already stored (except the type of coordinates used to save it), use the

WAYPOINT

Press the display a list of waypoints. Use the up and down arrow keys to point to the desired waypoint. Press the name, description, coordinates and/or warning radius of the waypoint.

menu key.

function.

WAYPTS/ROUTES

key, then the

EDIT

menu key. You may change the

WAYPT LI ST

UPDATE

EDIT

menu key to

Set the warning radius to zero if you want to remove the avoidance feature from this waypoint. In addition, you can press the

COORD

the previous section. Press the the waypoint from the 941X’s memory. (Note: You can’t erase it if it is used in a route—you must first erase it from the route. See “Changing a Route” on page 50 for more route editing information.)

Rev. D 4 — Creating Waypoints and Routes

menu key to correct the waypoint’s coordinates, as described in

4 — Creating Waypoint s and Routes Page 43

4 — Creating Waypoints and Routes4 — Creating Waypoints and Routes

ERASE

menu key to permanently erase

UPDATE

Page 52

Transferring

Waypoints to a

If you store a large number of waypoints or routes in the 941X, or if your waypoints are the only records you have of important locations, you should consider making a copy of them by transferring them into a personal computer using special transfer software (provi ded by a th ir d pa rt y vendor) and a Northstar loader cable (part #1100-LC). With this system, waypoints and routes can be copied, edited or plotted, and, most importantly, can be reloaded into your 941X in the event they are accidentally erased or lost due to equipment failure. Consult your authorized Northstar dealer for software and cable ordering information.

Creating

Routes

Page 44 4 — Creating Waypoints and Routes

A route is a sequence of waypoints stored in the 941X. You can store up to a maximum of 500 routes in the 941X’s memory. There are two methods by which you can create a route: 1) constructing a route from waypoints already stored in the 941X’s memory, and 2) saving a route as you travel it.

You may create a route from the waypoints stored in the 941X’s memory by first pressing the

ROUTE LIST

displayed.

4 — Creating Waypoints and Routes Rev. D

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WAYPTS/ROUTES

menu key. The names of any routes already stored are

key, and then pressing the

Page 53

Press the

NEW

menu key. A screen is displayed asking you to enter the

name of the new route.

route name

Enter the name of the new route using the keypad and cursor arrow keys, as described on page 36, and press points screen will be displayed, ready for you to begin selecting waypoints to add to the route.

Rev. D 4 — Creating Waypoints and Routes

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4 — Creating Waypoints and Routes4 — Creating Waypoints and Routes

ENTER

. The

NEW ROUTE

way-

Page 54

inserting

waypoints

To add waypoints to the route, press the stored waypoints is displayed.

Scroll the waypoint list up or down using the cursor keys to designate the desired waypoint, and press route.

Press the NEXT LIST menu key, if you wish, to select different waypoints from the alpha points cannot be used as waypoints in a route.)

Repeat for each waypoint you wish to enter.

ENTER

alpha, local

local or saved

alphaalpha

locallocal

INSERT

. The selected waypoint is now in the

saved lists. (Avoidance

savedsaved

menu key. A list of

You can insert a waypoint in any part of a route. Waypoints are always inserted into the route at the point indicated by the arrow at the left of the screen. Move the arrow so that it is halfway between th e two existing waypoints of the route where you want the new waypoint to be located. Follow the “inserting waypoints” procedure above for inserting this new waypoint into the route.

creating new

waypoints

during route

entry

Page 46 4 — Creating Waypoints and Routes

You can also create a new waypoint as you enter it into the route. After pressing .from the you wish) and coordinates of your new waypoi nt. P ress waypoint is now part of the new r oute and stored among the waypoint lists in the 941X’s memory.

INSERT

4 — Creating Waypoints and Routes Rev. D

4 — Creating Waypoints and Routes4 — Creating Waypoints and Routes

from the

SELECT WAYPT

NEW ROUTE

screen. Enter the name (with description, if

waypoints screen, press

ENTER

. The new

NEW

Page 55

verifying entry

As waypoints are entered, the distance and bearing of each leg of your route are displayed on the of the entire route, press the to use these two features to check that the route matches your expectations, ensuring that no erro rs were made in selecting waypoints.

The entire route is displayed, with the plotter scale automatically adjusted to show all of the waypoints.

NEW ROUTE

QUICK PLOT

screen. To see an overhead plot

menu key. It is good practice

Saving a Route

To see more detail about a portion of the route, use the

PREV WAYPT

and towards the beginning. Use smaller or larger area . Press to the previous screen.

A second way to create a route is to travel the length of th e desir ed route, pressing the route. The 941X's ess. In summary, you first tell the 941X tha t you wish t o save a route as you travel, then press the and then tell the 941X to stop saving the route when you come to th e end of the route.

First, press the

LIST

menu key to access route functions. The names of any routes already stored are displayed:

menu keys to advance along the route or move back

SAVE/MOB

button at each location you wish to store in the

SAVE ROUTE

SAVE/MOB

WAYPTS/ROUTES

ZOOM IN

RETURN

when finished viewing, to go back

function makes this a very simple proc-

button as you pass each waypoint,

key, and then press the

and

ZOOM OUT

NEXT WAYPT

to display a

ROUTE

Rev. D 4 — Creating Waypoints and Routes

4 — Creating Waypoint s and Routes Page 47

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Page 56

Press the

SAVE

menu key on the lower right of the display to instruct the 941X to begin saving a route automatically. A screen is display ed asking you to enter the name of the new route to be saved.

route name

Enter the name of the new route to be saved, using the keypad and cursor arrow keys, and press

ENTER

“SAVING TO: [route name]” at the bot tom of the firming that your route is now being saved.

Page 48 4 — Cre ating Waypoints and Routes

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. The 941X displays the message

ROUTES

screen con-

Page 57

storing

waypoints

As you pass the location of each new waypoint, press the key to the left of the display (not the the screen). The boat's location will be saved as a waypoint in the unit's memory, and the waypoint will automatically be added to the route being saved. The waypoint will be stored with a na me similar to parentheses ( ) indicate that the waypoint is par t of a saved route, and the four-digit number is used to uniquely identify each waypoint. Each waypoint is automatically given a description consisting of the time and date when the waypoint was stored.

SAVE

menu key in the lower right of

SAVE/MOB

(0001)

. The

You can access any of the 941X’s navigating functions while you are saving a route automatically, with the exception of editing the route you are presently saving. If, at any time, you are unsure as to whether you are still saving a route or not, press the

ROUTE LIST

ently saving a route, the message “SAVING TO: ” will be at the bottom of the screen.

ending the route

Rev. D 4 — Creating Waypoints and Routes

When you have reached the end of your new route, or if you wish to stop automatically saving the route at any time, go to the you are not presently displaying it), as described a bove. Press the

SAVE

menu key. The 941X will prompt you with a question window, asking if you want to “STOP SAVING TO ROUTE XXX?”. P ress for “YES.” The “SAVING TO: ” message at the bottom of the screen is extinguished.

4 — Creating Waypoint s and Routes Page 49

4 — Creating Waypoints and Routes4 — Creating Waypoints and Routes

menu key to display the

WAYPTS/ROUTES

ROUTES

screen. If you are pres-

ROUTES

key, then the

screen (if

STOP

ENTER

Page 58

Changing a

Route

To make a change to a route stored in the 941X's memory, use the

ROUTE

menu key to display the

Use the up or down cursor keys to point to the route you wish to ch ange. Press the

function. Press

EDIT

key. The route name is displayed.

WAYPTS/ROUTES

ROUTES

screen.

and then the

ROUTE LIST

EDIT

If you wish to change the route’s name, do so now, th en p ress not, press

A screen appears which displays the wayp oints in the route and allows you to insert or remove waypoints from the route.

Page 50 4 — Creating Waypoints and Routes

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ENTER

to continue.

ENTER

. If

Page 59

inserting

waypoints

To insert a new waypoint, use the up and down cursor keys to move the pointer to the spot between the two existing waypoints where you want to make the insertion, and press th e waypoints is displayed.

Move the cursor to select the waypoint from the displayed list, and press

ENTER

. You will see the selected waypoint now in your route.

INSERT

menu key. A screen listing

removing

waypoints

editing a route

you are

following

other waypoint

functions

To remove a waypoint from the route, use the up and down arrow keys to move the pointer to the waypoint, and press the and then

If you make changes to a route you are currently navigating along, remember that the modified route is stored back in the 941X’s memor y, but these changes do not appear in the copy of the route the 941X is following.

To make these changes take effect, you must start following the route again (see page 59).

To display each waypoint’s coordinates instead of its name and description—while editing or creating a route—press the key.

ENTER

REMOVE

NAME/COORD

menu key,

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Page 60

To plot an overhead view of the route, press the key.

QUICK PLOT

Page 52 4 — Creating Waypoints and Routes

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Page 61

Waypoint and Route

Navigation

Quick-Start Waypoint 54

Navigating to Waypoints 55

Navigating Along Routes 59

Restarting the Course Line 61

In this section, we’ll begin navigating to specific waypoints and along routes, and sho w you how to get back on cour se, or follow a new course line to your destination.

Rev. D 5 — Waypoint and Route Nav

5 — Waypoint and Route Naviiiigation

5 — Waypoint and Route Nav5 — Waypoint and Route Nav

gation Page 53

gationgation

Page 62

Quick Start

Waypoint

he 941X’s “Quick Waypoint” feature allows you to enter coordinates

and start navigating in one quick and easy sequence.

Press the menu key. A screen for entering waypoints appears.

Key-in the coordinates of the way point (just as you would norma lly store a waypoint) and press

The 941X stores the waypoint as a “–QUIK–” waypoint, and will immediately begin navigating to it.

WAYPTS/ROUTES

ENTER

key, and then press the

twice.

QUICK WAYPT

coordinates

Page 54 5 — Waypoint and Route Navigation

To change the type of coordinates you want to enter—from lat/lon, to distance and bearing, or to loran TDs—p ress the key to show the type you wish to use.

Coordinates may be entered as:

1. latitude/longitude of any point in the world

2. distance and bearing from “here” (your present position), or from any waypoint in the 941X’s memory

3. loran TDs (make sure the GRI displayed is correct; change it if necessary).

The coordinates you enter will be stored in the 941X's memory as a waypoint named “–QUIK–.” This waypoint’s coordinat es will be overwritten the next time a QUICK waypoint is entered.

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5 — Waypoint and Route Navigation5 — Waypoint and Route Navigation

COORD TYPE

Page 63

You can specify a waypoint to navigate to, and store it permanently in the 941X’s database in one operation, if you like. While in the sor arrow up to the waypoint’s name and change it from

-QUIK-

make a previously-ent ered QUICK waypoi nt become a perm anent waypoint, just go to a waypoint list screen and edit the name (and description, if you wish).

QUICK WAYPT

to its permanent name before pressing

WAYPOINT TIP

entry screen, just move the cur-

ENTER

. To

Navigating to

Waypoints

To navigate to a waypoint already stored in the 941X, first display it using one of the four waypoint list scr eens: pr ess

WAYPT LI ST

the move the large arrow on the left of the screen so that it points to the waypoint you want to navigate to. Then press th e

ENTER

then

Since the waypoints you navigate to are usually nearby, the LOCAL waypoint list is often the best list to use for finding the waypoint in the database.

menu key. Use the up and down cursor arrow keys to

WAYPOINT TIP

WAYPTS/ROUTES

GO TO

menu key, and

, then

The 941X will automatically swi tch to th e mation for navigating to the waypoint. You can also press the to display this information at any time. Two versions of the screen are available to choose from.

Rev. D 5 — Waypoint and Route Navigation

5 — Waypoint and Route Navigation Page 55

5 — Waypoint and Route Navigation5 — Waypoint and Route Navigation

STEER

display to show infor-

STEER

key

Page 64

choosing a

steering screen

The first distance at the bottom of the screen (how far off your intended course line you may be) combined with numeric information depicting the distance to your destination waypoint, your present bearing to that waypoint, your present SOG, and your present COG.

The “ the waypoints between you and the destination waypoint, and your position relative to the course line for precision steering. Both steering screens are intended to guide you precisely along a course line which might follow a harbor channel, or a line between shoals and sandbars.

STEERING

3-D

” steering screen is a waypoint “heading-up” display showing

screen is a traditional display showing cross-tr ack

distance and

bearing

other

information

Page 56 5 — Waypoint and Route Navigation

The first waypoint, along with your Speed-Over-Ground and Course-Over-Ground on the upper part of the readout. The digits a re large and can be read from a distance. An arrow between the SOG and COG displays points upwards when the trend of your speed is increasing, and down when it is decreasing.

The center of the screen has a user-selectable area which can be set to display any of the information listed below. Press the middle menu key to change the type of data displayed:

5 — Waypoint and Route Navigation Rev. D

5 — Waypoint and Route Navigation5 — Waypoint and Route Navigation

STEERING

screen displays your distance and bearing to the

Page 65

11112

3333

In the first steering screen above, a line extends from the data box in the center of the screen to a menu key. Each press of the menu key changes the data displayed in the box among three choices, as follows:

1. Estimated Time En Route (ETE) to the waypoint, and Estimated Time and Date of Arrival (ETA)

2. Speed of Advance (SOA) and Heading Correction

3. Waypoint’s name and description, and its coordinates

off-course

distance

Rev. D 5 — Waypoint and Route Navigation

The lower part of the screen displa ys your off-course distance, using a picture of your boat to show your distance from the course line. In addition, the direction of the boat on the screen indicates the direction your boat is actually traveling. (Note: this may not be the same as your heading if any current or wind is present.) When the picture of your boat points towards the course line, you are moving closer to the line. Wh en it points parallel to the course line, you are keeping a constant distance from the line. When it points away from the course line, you are moving further from the line.

Your distance from the course line is also di splayed in numbers at the bottom of the screen. See page 85 for customizing the cross-tr ack disp lay format.

5 — Waypoint and Route Navigation Page 57

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Page 66

Two vertical lines near the edge of the screen indicate the limits of offcourse distance. An alert message will be given if these limits are exceeded, and the image of your boat will flash on and off. Press the button to display the alert message, then the

CLEAR ALARM

STAR

menu key

to acknowledge and clear it.

As you pass a wa ypoint while following a route, t he image of the boat may swing around vigorously as it points to the waypoint you are passing. When the 941X switches to the next waypoint, the boat image will snap back to pointing straight ahead.

3-D STEER

The

display features a three-dimensional view of your boat,

NOTE

the current waypoint, the course line t o the waypoint, and the loca tions of any other nearby waypoints. It is intended t o pr ovide a compr eh ensive picture of your progress toward the waypoint.

Page 58 5 — Waypoint and Route Navigation

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Page 67

Navigating

Along Routes

starting the

route

To follow a route that has been stored in the 941X’s memory, press th e

WAYPTS/ROUTES

sor keys to select the route you wish to follow, and then press the menu key. The first four waypoints of the route are displayed.

key, then the

ROUTE LIST

menu key. Use the cur-

11112

Notice that the arrow shape alternates as you move the cursor up and down. The first arrow shape designates a single wa ypoint of the route. The second designates a leg connecting two wa ypoints. The two shapes allow you to start following a route in either of two ways:

1. DIRECT TO WAYPOINT:

DIRECT TO WAYPOINT: You may navigate directly from your pre-

DIRECT TO WAYPOINT:DIRECT TO WAYPOINT:

Rev. D 5 — Waypoint and Route Navigation

sent position to a designated waypoint. To start on a waypoint other than the first, use the cursor keys to move the pointer to the desired waypoint, as in screen #1 above. Press the GO menu key,

ENTER

then

2. ALONG A LEG:

ALONG A LEG: You may tell the 941X that you want to navigate

ALONG A LEG:ALONG A LEG: along a designated leg of the route. Move the cursor down until it

5 — Waypoint and Route Navigation Page 59

5 — Waypoint and Route Navigation5 — Waypoint and Route Navigation

Page 68

changes to a connecting arrow between the two waypoints, as in screen #2 above. Press the

To start following the route, select th e waypoint or leg you wa nt to start on, press the GO menu key, then

menu key, then

ENTER

planning ETA to

any waypoint

Before you actually start the route, you can display planning information about the route in the time required to travel to the selected waypoint is displayed near the top . As you scroll the pointer up or down, the ETA wi ll change for each wa ypoint. This estimate is based on the Speed-Over-Ground figure displayed at the bottom of the screen.

To change this figure, press the new value to be used in calculating the time. Use the cursor arrow keys again to scroll through the Estimated Times of Arrival for different waypoints of the route.

To access the proceed as though you were going to follow a route by pressing the

WAYPTS/ROUTES

wish to view. Press GO to display the ETA of each waypoint in the route and the out actually following the route, press any function key.

USUAL SOG

GO ALONG ROUTE

USUAL SOG

and waypoint

key, then

window at the bottom of the screen. To exit with-

ROUTE LIST

screen. An estimate of the

menu key and enter the

ETA

features from any screen,

, then select the route you

Page 60 5 — Waypoint and Route Navigation

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Page 69

distance &

bearing

The distance and bearing of each leg are displayed near the center of the screen.

waypoint

coordinates

quick plot

To display the coordinates of each waypoint in place of the name and description, press the

To plot an overhead view of the route, press the key. When displaying the plot, you may use the

PREV WAYPT

wards the beginning.

ZOOM IN

Use When you have finished looking at the plot, press the previous screen.

NAME/COORD

menu keys to advance along the route or move back to-

ZOOM OUT

and

menu key.

QUICK PLOT

NEXT WAYPT

to display a smaller or larger area.

RETURN

and

to go back to

Restarting the

Course Line

Rev. D 5 — Waypoint and Route Navigation

When navigating from one waypoint to a nother, you may find you have wandered off the intended course line. Perhaps you may h ave avoided an obstacle, or simply drifted slightly off-course. Whenever you are offcourse for any reason, you may choose either of two meth ods for getting back on course.

After passing the obstacle, you may steer the boat back to the original course line using the Cross-Track error display (Course 1 below), and continue to the waypoint.

5 — Waypoint and Route Navigation Page 61

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Page 70

If you do not need to return to the original course line, you can continue directly to the waypoint (Course 2) using the restart function described below.

To restart your course line from your present positi on, display the

LOG

screen or the menu key, then the to extend from your present position directly to the next waypoint, resetting your cross-track error to zero.

POSITIO N PLOTTER

ENTER

key. The 941X will recompute the course line

screen. Press the

NAV

RESTART

Page 62 5 — Waypoint and Route Navigation

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Page 71

The NAV LOG Function

What NAVLOG Does 64

Logging Your Trip 65

Changing Your Trip 65

Adding Waypoints to the Trip 66

The Northstar 941X’s NAV LOG function provides a quick and easy way to check on yo ur pr ogr ess along a t rip, and to make changes to it while you travel.

Rev. D 6 — The NAV LOG Function

6 — The NAV LOG Function Page 63

6 — The NAV LOG Function6 — The NAV LOG Function

Page 72

What NAV LOG

Does

HE Northstar 941X’s NAV LOG feature helps you plan and log your

trip. It contains the actual series of waypoints that you follow along your route. When you navigate to a waypoint or along a route from the 941X’s memory, the string of waypoints are copied into the NAV LOG, which acts as a kind of “scratchpad” for monitoring your progress. You can modify NAV LOG’s route in any way you want without affecting the original route, which remains safely stored in the unit’s memory.

NAV LOG provides two main functions: It shows your progress along your trip, and it lets you easily change the remainder of your trip.

ETA and ETE

pass status

restart

Page 64 6 — The NAV LOG Function

Information for safe and efficient planning of your trip i s upda ted as you travel. Your Estimated Time of Arrival (ETA) at the last waypoint in the route is shown at the top of the screen, and the Estimated Time Enr oute (ETE) to each waypoint is shown below each waypoint name.

A darkened arrow connecting the right ends of two waypoint boxes indicates you have completed that leg of the trip.

You may restart at any leg or to any waypoint of the route by moving the cursor arrow to the waypoint or leg and pressing the key.

6 — The NAV LOG Function Rev. D

6 — The NAV LOG Function6 — The NAV LOG Function

RESTART

Page 73

reversing the

trip

You can reverse the trip at any time (navigating to route waypoints in reverse order) by pressing the

REVERSE

menu key.

appending

waypoints

Logging Your

Trip

Waypoints may be added to the trip by pressing the menu key. Any waypoints added to the trip in NAV LO G are not permanently appended to the route in the 941X’s memory. To ma ke per manent changes to the route, you must use the EDIT ROUTE functions, as described on page 50.

Waypoints are automatically entered and organized in NAV LOG when you first navigate (GO) to a waypoint or along a route.

Press the are currently navigating along. Use the up and down cursor arrow keys to scan through the entire li st to show any waypoint you wish. The distance and bearing of each leg is displayed. For each waypoint, you can display either the waypoint’s description, or the time of arrival at the waypoint. Press the

The time of arrival displayed is the Estimated Time of Arrival (based on your current speed) for waypoints you have not yet passed. Actual Times of Arrival are shown for waypoints you

NAV LOG

Remember, estimated times are just that—estimates—and may be inaccurate. This is because your Speed-Over-Ground will be affected by any changes in direction, even slight changes brought about as you pass through varying currents.

key at any time to display the list of waypoints you

NAME/ETA

menu key to select one or the other.

passed.

have

APPEND WAYPT

Changing Your

Press the rent trip. You may modify the remainder of your trip by:

Trip

Rev. D 6 — The NavLog Function

NAV LOG

• adding a waypoint to the end of the trip

• skipping to any waypoint within the trip

• reverse the trip from present position to follow it back to the be-

ginning

6 — The NavLog Function Page 65

6 — The NavLog Function6 — The NavLog Function

key, as above, to display the waypoints of your cur-

Page 74

NAV LOG

Under You can easily read the direction of the next leg of your trip from this display.

, the distance and bearing of each leg are displayed.

Adding

Waypoints to

the Trip

Press the add a waypoint to the end of the trip, press of the waypoints stored in memory is displayed. Use the up and down cursor arrow keys to select the desired waypoint. (Press you wish, to display the waypoints list in a different order.) Press to add the waypoint to the NAV LOG. Repeat for any other waypoints you want to add.

NAV LOG

key to display the waypoints of your current trip. To

APPEND WAYPOINT

NEXT LIST

. A list

, if

ENTER

Page 66 6 — The NAV LOG Function

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Page 75

Other Special Functions

Alarms 68

Screen Backlighting 71

TideTrack™ 71

Internal Differential Beacon Receiver 74

This section covers several special functions that enable you to: change the 941X’s audible alarms and screen appearance; navigate using the unique TideTrack™ feature; get the most out of the high-precision positioning capabilities of your internal or external Differential GPS (DGPS) receiver.

Rev. D 7 — Other Special Functions

7 — Other Special Functions Page 67

7 — Other Special Func tions7 — Other Special Functions

Page 76

everal special 941X functions are controlled by the

key (

). These include alerts and alarms, TideTrack™ functions,

and setup functions.

STAR

function

Alarms

The Northstar 941X has a number of automatic alarms that can alert you of special situations. For example, when you are approaching a waypoint, the 941X signals you with a distinctive “beep” and a flashing exclamation point symbol on the screen.

At any time, you can press the

ALARMS & BACKLIGH T

screen which displays the cause of the most

STAR

button (

) to access the

recent alarm. The 941X’s alarm types and descriptions are:

AUTO

TYPE DESCRIPTION

ARRIVE

PASS

CHANGING

AVOIDANCE AREA

ANCHOR DRAG

NO LORAN FIX

DGPS LOST

NO GPS FIX

NO LORAN DATA

NO GPS DATA

POOR LORAN FIX

CROSS-TRACK

LIMITS EXCEEDED

you have come within 900’ of the arrival circle of the c urrent waypoint (arrival circle radius set from

ALARMS & BACKLIGHT

screen) you have entered the arrival circle of the current waypoint while navigating to waypoint, perpendicular to track pass ed, but arrival circle was not entered switching to next leg of route (“NOW NAVIGAT ING TO . . . ”) avoidance area circle has been entered anchor is dragging beyond limit set from

BACKLIGHT

no position fix received from external loran

DGPS data timeout exceeded “ no position fix from GPS " communicati on failure with external loran communicati on f ai l ure with GP S " BLINK, CYCLE or LOW SNR detected at loran off-course in excess of limits set in

ALARMS &

CROSS TRAC K ALARM

screen

CLEAR?

YES, after 5

seconds

YES, after 5

seconds

YES, after 5

seconds

YES, after 5

seconds

NO: potential

hazard ahead

NO: requires

immediate

attention

YES, when

condition

clears

only when

within limits

Page 68 7 — Other Special Functions

7 — Other Special Functions Rev. D

7 — Other Special Func tions7 — Other Special Functions

Page 77

Though most alarm conditions are “auto clearing” after approximately five seconds, and do not require any user action, two alarms—

AVOIDANCE AREA

before the exclamation point can be cleared from the screen. The most recent instance of an alarm type (waypoint, communications,

avoidance area, anchor and cross-track alarms) is retained in the 941X’s memory. This is helpful for viewing those “auto-clear” alarms that you may have been unable to acknowledge before the flashing exclamation symbol was automatically cleared. Each successi ve press of the

ALARM

alarm. Four of the alarm controls are adjustable, as described below. To change

any of these, use the up and down cursor keys to move the arrow on the screen to the control you want to edit. Press the key. Use the up or down arrow keys to select the status you want, and finally press

menu key displays the most recent message for each type of

ENTER

ANCHOR WATCH

and

—must be acknowledged

CLEAR

EDIT ALARM

alarm audio

Rev. D 7 — Other Special Functions

The audio beep that alerts you to alarm conditions can be turned on or off.

1. Select

2. Press the

3. Use the up/down cursor arrow keys to display

4. Press

ALARM AUDIO

EDIT ALARM

ENTER

7 — Other Special Functions Page 69

7 — Other Special Func tions7 — Other Special Functions

to make your selection, or

, using the up/down cursor arrow keys.

menu key.

OFF

or ON.

OFF

to leave it unchanged.

Page 78

ALARM AUDIO

When any of the alarm conditions turned ON at the screen.

is set to ON, the 941X will audibly alert you to

ALARMS & BACKLIGH T

anchor watch

cross track

alarm

The anchor watch feature of the 941X will sound an alarm if the unit detects that the boat has moved a specified distance away from an initial position.

1. Press the is dropped.

2. Press

3. Move the cursor arrow to

ALARM

4. Use the up/down cursor keys to turn the alarm ON.

5. Move the cursor to the right and use the keypad to specify the distance the boat can be expected to move on its anchor cha in (plus a safety factor to allow for GPS or loran inaccuracy).

6. Press

Remember to turn the moving away from the anchor drop point.

The cross track alarm allows you to specify the maximum distance the boat will be permitted to move from the track line without sounding an alarm. You can turn the cross track alarm on or off, and specify the alarm distance from the track line.

DROP ANCHOR

ENTER

in response to the question window prompt.

menu key.

menu key at the spot where the anchor

ANCHOR ALARM

ANCHOR WATCH

and press the

alarm off before intentionally

EDIT

1. Move the cursor arrow to

Page 70 7 — Other Special Functions

2. Press the

3. Choose whether you want the cross-track alarm the up/down cursor keys.

4. If you want to change the limit at which the cross-track alarm will alert you, use the right arrow cursor key to move to the digits field.

5. Using the keypad, specify the distance at which you want to be alerted, and press

7 — Other Special Functions Rev. D

7 — Other Special Func tions7 — Other Special Functions

EDIT ALARM

ENTER

CROSS TRACK

menu key.

OFF

with

Page 79

arrive radius

ARRIVE RADIUS

The fied distance of the next waypoint. You can specify the distance of the radius around waypoints down to 0.01 nm.

1. If you want to change the limit at which the arrive radius alarm will alert you, move the cursor arrow to

alarm signals you when you come within a speci-

ARRIVE RADIUS

dgps alarm

Screen

Backlighting

2. Press the

3. Using the keypad, specify the distance at which you want to be alerted, and press

NOTE: Keep this dista nce ver y sm all b eca use th e 941X wi ll aut oma ti ca lly begin to sequence to the next waypoint when you come within the arrival distance you have set for the current waypoint.

DGPS ALARM

The ential corrections beyond the DGPS data timeout limit. (See “DGPS data timeout,” beginning on page 89, for details.)

1. If you want to activate the audible DGPS timeout alarm, move the cursor arrow to

2. Press the

3. Use the up/down cursor keys to turn the alarm on or off, and press

ENTER

To change the level of backlighting of the unit’s screen and keys:

1. Press the screen.

EDIT ALARM

signals when the 941X has operated without differ-

DGPS ALARM

EDIT ALARM

STAR

key to display the

ENTER

menu key.

ALARMS & BACKLIGHT

2. Press the

3. Press the

TideTrack

Rev. D 7 — Other Special Functions

The 941X calculates tide information for any of over 3,000 NOS/NOAA tide stations. The entire U.S. coastline—including Alaska and Hawaii—is covered, plus many Caribbean islands and western Canada. Tides may be

7 — Other Special Functions Page 71

7 — Other Special Func tions7 — Other Special Functions

BRIGHT DIM

menu key to make the lighting brighter.

menu key to dim the lighting.

Page 80

displayed for any date from 1994 to 2010. Dat a is from the official tide table predictions and should be as accurate as the printed tables. (Please refer to 20852, for more information on tides.)

Tide Tables

, published by the NOS/N OAA, Rockville, Maryland

To use TideTrack, press the displayed.

The water height for any 24-hour period is displayed for the selected NOAA tide station.

At the top of the screen the selected tide station and the selected day ar e displayed.

The center of the screen shows a graphic representation of the tide height for the entire day. Maximum and minimum heights are shown as dashed horizontal lines labeled with the height in feet. Mean Lower Low Water (MLLW) is shown as a solid line near the bottom of the picture. A vertical line and arrow are positioned to show the tide level for the current time.

STAR

key until the TideTrack graphic is

At the bottom of the screen, the times of the day’s high and low tides are shown for that location, along with the height at the present time.

choosing a

nearby tide

station

Page 72 7 — Other Special Functions

You may display tide information for any of over 3000 NOAA tide stations stored in the 941X. You can select from any of t he ni ne ti de sta tions closest to your present position, or you may select from any of ni ne tide stations closest to any waypoint stored in the 941X.

7 — Other Special Functions Rev. D

7 — Other Special Func tions7 — Other Special Functions

Page 81

To choose a nearby tide station, press the

TIDE TRACK

screen.

CONFIG

key while viewing the

choosing a

distant tide

station

Press the will search for the nine closest stations to your present position and present a list like the following, organized by closest station at the top:

Use the up and down arrow keys to point to the desired station, and press tides for that station.

The 941X will display NOAA tide stations within 100nm of any waypoint stored in its memory. (You can always stor e a waypoint just for the purpose of locating tide stations in that area, at a later date. Refer to “Creating Waypoints,” on page 37, for more information on storing a waypoint.)

CHOOSE CLOSEST TIDE STATION

ENTER

twice to return to the

TIDE TRACK

menu key. The 941X

screen and display the

To choose a tide station near a waypoint, press the

Rev. D 7 — Other Special Functions

TIDE TRACK WAYPOINT

7 — Other Special Functions Page 73

7 — Other Special Func tions7 — Other Special Functions

screen. Press the

menu key. A list of the 941X’s waypoints is displayed.

CONFIG

CHOOSE CLOSEST STATION TO

key on the

Page 82

selecting a day

Use the up or down cursor arrow keys to point to the desired waypoint, and press tide stations to this waypoint. Now, use the up and down arrow keys to point to the desired station, and press

TIDE TRACK

The date.

ENTER

screen and display the tides for that station.

TIDE TRACK

. The 941X will search for, and present, the nine closest

ENTER

screen normally displays tide information for today’s

twice to return to the

Internal

Differential

Beacon

Receiver

To enter a different date, press the

TRACK CONFIGURATION

menu key. The first character of the present tide date flashes. If necessary, press the right cursor arrow to move to the month or digit you wish to change. To change a digit, press that key on the keypad. To change the month, use the up and down cursor arrow keys. When the date is correct,

ENTER

press

As we previously discussed in “Comparing GPS and Loran,” beginning on page 5, use of differential corrections significantly enhances the accuracy and performance of your 941X. One source of differential corrections is Northstar’s fully automatic beacon receiver, which may be connected externally (part #8800) to the 941X, or contained internally (#8500). Or, you may connect another source of corrections externally (see page 124 for further details on interfacing to external sources of differential corrections).

The Northstar beacon receiver takes corrections broadcast by shorebased marine radio beacons situated along most of the U.S. coastline.

twice. Tide information for the new date is now displayed.

screen is displayed. Press the

CONFIG

menu key; the

TIDE

NEW DATE

Page 74 7 — Other Special Functions

7 — Other Special Functions Rev. D

7 — Other Special Func tions7 — Other Special Functions

Page 83

These corrections are used by your 941X to improve its position accur acy to 10 meters—or better—with 2-5 meters accuracy commonly available.

Differential corrections are invaluable when navigating in narrow or congested areas (such as ports and waterwa ys), or whenever extr eme accuracy is required for locating a precise area (retrieving lobster pots, returning to a diving spot, etc.).

Northstar beacon receivers require no manual operation. They automatically tune to the appropriate beacon frequency as you move from one beacon coverage area to another, or as weather conditions change. Available radio beacon signals are constantly evaluated for signal quality by the receiver, and only the best station is selected. As you travel, the Northstar beacon receiver is prepared to switch to another frequency automatically, as conditions require.

automatic mode

manual mode

The 941X, with a Northstar beaco n receiver, enters automatic differential mode as soon as SC-104 DGPS corrections are received and requires no further supervision, as far as differential operation is concerned. The beacon receiver maintains automatic operation by using two independent receiver channels. Channel 1 tracks the best available beacon signal (the one with the lowest data error rate) and sends the demodulated DGPS corrections to the 941X GPS receiver. Channel 2 scans the entire beacon frequency band (283.5 to 325kHz), locating and measuring received DGPS beacon signals. The unit then stores this information as a DGPS beacon “directory” in its battery-powered memory.

If the signal being received and monitored by Channel 1 degrades for any reason, the unit tries to select a better frequency from its beacon memory. This allows it to switch to the best beacon signal before your GPS accuracy can be affected.

Automatic mode can normally be used for all but specialized applications.

At any time, you can override automatic beacon station selection of the beacon receiver by issuing tuning commands from the keypad. In man

continuously

Rev. D 7 — Other Special Functions

7 — Other Special Functions Page 75

7 — Other Special Func tions7 — Other Special Functions

Page 84

ual mode, the beacon receiver will output DGPS corrections only from the selected station. Though the need for manual operation is rare, it is easily accessed from your 941X keypad.

To manually choose a beacon, you must select the frequency and baud rate (the beacon’s data transmission speed) of the desired beacon.

DGPS data

timeout

1. To first change the frequency, press the

USER CUSTOMIZATION

the

2. Press the

BEACON FREQUENCY

3. Press the down cursor key once, to change from “

MANUAL

“ right of the word “

4. Use the right cursor key to highlight the digits you wish to change. Enter the appropriate frequency and pr ess done.

You may also manually set the baud rate for the selected beacon frequency.

BAUD RATE

A non-Northstar external beacon receiver cannot be manually controlled by the 941X, unless it supports the MX50R control protocol. Refer to the beacon receiver manufact urer’s instructions to determine if this control protocol is supported.

If the beacon receiver stops receiving differential data, the 941X will continue navigating for a short time using the old DGPS corrections. Reception of the DGPS data can be interrupted by bad weather, severe thunderstorms, extreme distance from the beacon, etc.

RECEIVER OPTIONS

.” A beacon transmitter frequency will appear to the

MANUAL

However, it is strongly recommended to leave the

setting at

AUTO

screen.

and press the

.”

NOTE

STAR

key until you display

menu key. Move the cursor to

EDIT

menu key.

AUTO

” to

ENTER

when you are

BEACON

You may allow the 941X to navigate for a set period of time using this old data with no DGPS interruptions. To change the data “timeout” period, refer to page 89.

Page 76 7 — Other Special Functions

7 — Other Special Functions Rev. D

7 — Other Special Func tions7 — Other Special Functions

Page 85

Customizing the 941X

Time of Day 78

Display Options 78

Navigation Options 82

Port Setup Options 90

Service Options 91

Geodetic Datum 94

his section explains the various options available to you

for customizing the way your 941X displays information to you, computes navigation data, and “ talks” to o ther devices. Each option is changeable at any time, according to your specific needs.

Rev. D 8 — Customizing the 941X

8 — Customizing the 941X Page 77

8 — Customizing the 941X8 — Customizing the 941X

Page 86

Time of Day

Press the time, date, local time zone, and time of today’s sunrise and sunset are shown.

Also displayed is the current time expressed as “GMT” (Greenwich Mean Time). Note that the day of the week in Greenwich, England may be different from the day in your local time zone (right screen, above).

To change the time zone used for the time display (both here and in other time displays), press th e down cursor arrow keys to select the desired zone and standard or daylight time. Press

STAR

key until you display the

ENTER

to use the new time zone.

TIME Z ONE

TIME OF DAY

menu key, and use the up or

screen. The

Display Options

To access the 941X’s display options, press the play the

Press the shown:

USER CUSTOMIZATION

DISPLAY OPTIONS

menu key. The following choices are

screen.

STAR

key until you dis-

Page 78 8 — Customizing the 941X

8 — Customizing the 941X Rev. D

8 — Customizing the 941X8 — Customizing the 941X

Page 87

To change any of the options (described below), select it by using the cursor keys to move the arrow at the left of the screen, and then press the

EDIT

menu key. The field will begin to flash, waiting for y ou to change it

using the up/down cursor keys or the keypad.

distance, bearing

dist/speed units

The 941X offers you the choice of calculating the distance and bearing to your intended destination as either a

RHUMB LINE

The shortest distance between a ny two points on the surface of a sph ere is called a Great Circle route. It appears as a curved line on a Mercator chart and is the default method of calculating distance and bearing to waypoints by the 941X.

Rhumb line navigation maintains a constant tr ue direction to your destination (seen as a straight line on a Mercator chart), but is a somewhat longer route to travel over great distances than the Great Circle calculation. A Rhumb Line course may be desired if a Great Circle route is likely to take you precipitously close to bad weather or an unavoidable land mass.

You may choose between nautical miles and knots, kilometers and kilometers per hour, or statute miles and miles per hour, for the 941X’s various distance and speed displays, respectively.

To change this option, press among the available choices. Press

CLEAR

EDIT

to leave the option unchanged.

GREAT CIRCLE

, then use the cursor keys to scroll

ENTER

to make your selection, or

route or a

Rev. D 8 — Customizing the 941X

8 — Customizing the 941X Page 79

8 — Customizing the 941X8 — Customizing the 941X

Page 88

time display

This option determi nes whether feet or meters will be used in

STEERING

the steering screens’ distance-to-waypoint displays when selected as the under NAVIGATION OPTIONS—see pages 85 and 86, respectively).

(DISPLAY OPTIONS)

(DISPLAY OPTIONS)(DISPLAY OPTIONS) Time of day may be displayed in either 12- or 24-hour format. The option

you select here affects all of the 941X’ s time-related displays, including high and low tides, sunrise/sunset, and ETA.

screen’s

STEER DIST PRECISION

NOTE

CROSS-TRACK

display, and in both option (both selected

HIGH

lat/lon display

max. save d waypoint #

To change this option, press among the two choices. Press to leave the option unchanged.

(DISPLAY OPTIONS)

(DISPLAY OPTIONS)(DISPLAY OPTIONS) You may adjust the precision of the 941X’s latitude and longitude posi-

tion displays from degrees, minutes and seconds (two digit places, or .XX

.XX), to degrees, minutes and thousandths of minutes (three digit places,

.XX.XX or .XXX

.XXX).

.XXX.XXX

To change this option, press among the two choices. Press to leave the option unchanged.

(DISPLAY OPTIONS)

(DISPLAY OPTIONS)(DISPLAY OPTIONS) The 941X automatically assigns a sequential waypoint number for each

point stored using the the designated value set using this function, the unit starts over at 1 (displayed as –S001–), and overwrites any old saved waypoint already designated as number 1. You can set the maximum number of saved waypoints which the 941X will store before overwrit ing old saved points (see below). For many applications, you may wish to set this maximum number to a small value, such as five or ten, provided y ou promptly rename any saved waypoints you wish to retain, before they are overwritten.

EDIT

ENTER

EDIT

ENTER

SAVE/MOB

, then use the cursor keys to scroll

to make your selection, or

, then use the cursor keys to scroll

to make your selection, or

button. When this number reaches

CLEAR

Page 80 8 — Customizing the 941X

8 — Customizing the 941X Rev. D

8 — Customizing the 941X8 — Customizing the 941X

Page 89

owner’s message

To change the maximum saved waypoint number:

1. Move the cursor to this option a nd press the cursor will begin to flash in the first digit field.

2. Using the numeric keypad, enter the value you want—up to a maximum of 199—and press enter a zero as the leading digit(s).

The 941X will now automatically number your saved waypoints up t o the value you have set, at which point it will then begin to overwrite previously-saved waypoints with your new ones.

(DISPLAY OPTIONS)

(DISPLAY OPTIONS)(DISPLAY OPTIONS) To provide a substantial measure of theft protection for your Northstar

941X, you may enter a personalized owner identification message using an access code mailed to you when you return your product registration card to Northstar. This function asks you to enter this special four-digit code before you can change the owner’s message.

You can enter your individual owner ID message once you have received your registered owner access code card:

ENTER

. For one- or two-digit values,

EDIT

menu key. The

1. Press the

CUSTOMIZATION

2. Go to

3. Press the

4. Enter the “access code” number from your Northstar ID card and

5. Enter the message (up to two lines) you want displayed each time

Your message remains unchangeable from this point on, without first entering your specific access code number and repeating the above procedure. The 941X will allow three attempts to enter the correct access code; after that, all operations will “freeze,” requiring the user to shut power off, then turn it back on again in order to resume functioning.

DISPLAY OPTIONS

OWNER’S MESSAGE:

you to enter your password.

ENTER

press flash.

you power-up your 941X, and press

STAR

key until you display the

screen.

and move the cursor arrow down to

EDIT

menu key. A question window will appear, asking

. The first character block of the owner’s message will

ENTER

USER

Rev. D 8 — Customizing the 941X

8 — Customizing the 941X Page 81

8 — Customizing the 941X8 — Customizing the 941X

Page 90

Press the screen.

RETURN

menu key to return to the

USER CU STOM IZATION

Navigation

Options

navigation

source

The following options control aspects of navigati on and the use of GPS and Differential GPS. Press the

CUSTOMIZATION

key to display the following choices:

To change any of the displayed opti ons, move the cursor arrow t o that item and press the available choices, or the keypad to enter specific values.

(NAVIGATION OPTIONS)

(NAVIGATION OPTIONS)(NAVIGATION OPTIONS) The 941X’s position displays and naviga tion to a waypoint a re based on

position information obtai ned from any one of four available naviga tion sources:

screen. Press the

EDIT

menu key. Use the cursor keys to scroll through

STAR

key until you display the

NAVI-GATION OPTIONS

USER

• GPS

• an external loran receiver

• Phantom Loran coordinates calculated from GPS coordinates, or

• “DEMO” mode.

Use the

Page 82 8 — Customizing the 941X

used. To change it, press the sor arrow keys to make your selection. Press or

NAVIGATION SOURCE

CLEAR

to leave the option unchanged.

8 — Customizing the 941X Rev. D

8 — Customizing the 941X8 — Customizing the 941X

option to select which source is to be

EDIT

menu key and use the up/down cur-

ENTER

when you are done,

Page 91

GPS

•

can be selected as the navigation source at any time.

EXTERNAL LORAN

to the 941X (and is operational).

PHANTOM LORAN

faced to the system, but you’d like to see your posit ion displayed in TD coordinates.

DEMO

mode is used to simulate a stationary position—namely, the unit’s last position fix—if you want to practice using the 941X without being on your boat or connected to an antenna. You may enter a waypoint with the name “DEMO” to establish a new demo position at that waypoint’s coordinates.

can be used if a loran receiver is interfaced

can be used if no loran receiver is inter-

magnetic

variation

If your 941X is equipped with an internal beacon receiver, differential GPS corrections (if available) will always be used when “GPS” or “Phantom Loran” is selected as the navigation source.

(NAVIGATION OPTIONS)

(NAVIGATION OPTIONS)(NAVIGATION OPTIONS) Compasses naturally point to t he

hundred miles from the Earth’s actual north pole. The difference between the two angles is known as you the option of choosing from True lates variation automatically, according to your location), and Manual (from 0° to 180°, East or West) settings. The fact ory default is magnetic, to coincide with your compass. Your navigation charts will indicate the approximate magnetic variation for each area.

Under most conditions, you’ll want the 941X to calculate the variation

automatically

variation is entirely adequate for use.)

bearings are usually required when using a gyrocompass.

True

The

manual

play must match an older or less accurate chart, or in remote areas (usually above 70° latitude) where magnetic calculations can be off by as much as a degree or more.

for your position. (Usually, the automatically-calculated

setting (1° to 180°) is available for those times when the dis-

NOTE

magnetic

magnetic variation

True (0°), Automatic

TrueTrue

north pole, which is several

Automatic (the 941X calcu-

AutomaticAutomatic

. The 941X offers

Manual

ManualManual

Rev. D 8 — Customizing the 941X

8 — Customizing the 941X Page 83

8 — Customizing the 941X8 — Customizing the 941X

Page 92

waypoint

switching (and

the arrive

radius)

EDIT

Press up/down cursor keys to choose AUTO, MANUAL or TRUE. When choosing MANUAL, move the cursor to the right to enter the value you want. Press unchanged.

(NAVIGATION OPTIONS)

(NAVIGATION OPTIONS)(NAVIGATION OPTIONS) The 941X can be set to advance automatically to the next waypoint upon

arrival at each waypoint, or it can be set to require manual switching. Manual switching may be desirable when maneuvering around a way-

point to find a lobster trap, or when trying to locate a buoy in dense fog. It allows you to maintain a constant display of distance and bearing information for the particular waypoint you are using, until you instruct the unit otherwise.

When set to automatic switching, the 941X will display new distance and bearing information for the next waypoint upon arrival at the previous one. It will immediately stop navigating when a lone waypoint—or the last waypoint in a route—has been passed.

To change the 941X’s mode of waypoint switching, position t he arrow to the left of the menu key. Use the cursor arrow key to select AUTO or MANUAL. Press

ENTER

to change the 941X’s magnetic variation setting. Use the

ENTER

when you are done, or

WAYPOINT SWITCHING

CLEAR

option and press the

to leave the option unchanged.

to leave the option

EDIT

You have “arrived” at a waypoint when you enter the circle determined by the waypoint’s of the end point of the current leg you are following. The 941X will signal that you have arrived by flashing the alert symbol (flashing exclamation point) in the lower-right portion of the display. You can either acknowledge the alert by pressing the

BACKLIGHT

you can wait until it automa tically clears it self once you have left the arrive circle. (See page 68 for more on the 941X’s various alarms.)

Page 84 8 — Customizing the 941X

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8 — Customizing the 941X8 — Customizing the 941X

ARRIVE RADIUS

screen, then pressing the

, or when you pass the perpendicular

STAR

key to display the

CLEAR ALARM

ALARMS &

menu key, or

Page 93

ARRIVE RADIUS

The ft.). To change it:

factory default is 0.02 nautical miles (approx . 120

geodetic datum

cross track full

scale

1. Press the screen.

2. Move the cursor arrow down to

EDIT ALARM

3. Enter the new value you want, then press leave the value unchanged.

(NAVIGATION OPTIONS)

(NAVIGATION OPTIONS)(NAVIGATION OPTIONS) The geodetic datum option contains all referenced datums according to

Defense Mapping Agency publications. To change the datum reference your 941X is using, pr ess th e

key at this option and use the up/down cursor keys to scroll through the alphabetic listing. When your choice is displayed, press complete listing of 941X datums is found at the end of this chapter, beginning on page 94.)

(NAVIGATION OPTIONS)

(NAVIGATION OPTIONS)(NAVIGATION OPTIONS)

STEERING

The your needs, whether you are navigating in open water s or attempting to maneuver through a tight channel.

STAR

key to display the

menu key.

screen cross-track display limits may be adjusted to suit

ALARMS & BACKLIGHT

ARRIVE RADIUS

ENTER

and press the

, or

ENTER

CLEAR

EDIT

. (The

Adjustments to the display limits (shown at the bottom of the screen) enable you to monitor your progress in increments of feet or meters, if you wish, as opposed to the normal settings of tenths of miles, tenths of nautical miles or kilometers.

The format available to you depends on the selection made in the

DISTANCE/SPEED UNITS

screen. The corresponding choices are:

DISPLAY OPTIONS SETTING CROSS-TRACK OPTIONS

MI / MPH 1000 FT, 2000 FT, ½ MILE

NM / KNOTS 1000 FT, 2000 FT, ½ N. MILE

KM / KPH 200 Meters, 1KM, 2KM

Rev. D 8 — Customizing the 941X

8 — Customizing the 941X Page 85

8 — Customizing the 941X8 — Customizing the 941X

setting under the

DISPLAY OPTIONS

Page 94

CROSS-TRACK FULL SCALE

The

STEERING

to the

The options represent the entire distance limit on your screen, from complete left to complete right. Therefore, a cross-track distance setting of 1,000 feet will display 500 feet to either side of your track line, while a choice of ½ mile will display limits of ¼ mile to either side, and so forth.

screen, and not to the 3-D steer screen.

NOTE

display formats apply only

steer dist

precision

To change the setting, press the cursor keys to scroll through the availa ble choices. Press you are done, or modify the feet or meters in the cross-track display.

(NAVIGATION OPTIONS)

(NAVIGATION OPTIONS)(NAVIGATION OPTIONS)

STEER DIST PRECISION

The to the distance-to-waypoint displa y on the screens. Situated in the upper-left portion of the screens, the distance-towaypoint is normally displayed in tenths of miles or kilometers.

By changing the

HIGH

, the distance-to-waypoint display will increment in feet or meters, once you have come within 1.0 mile or kilometer of the destination waypoint.

CLEAR

DISPLAY OPTION

STEER DIST PRECISION

to leave the option unchanged. If necessary,

EDIT

menu key and use the up/down

ENTER

setting to enable your choice of either

function offers an extra level of accuracy

STEERING

option from

and

when

3-D STEER

NORMAL

Page 86 8 — Customizing the 941X

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8 — Customizing the 941X8 — Customizing the 941X

Page 95

To change the key and use the up/down cursor keys to scroll among the choices of

HIGH

or leave the option unchanged.

Both steering information screens will now reflect your prefer ence when you are less than one mile or kilometer from your destination.

STEER DIST PRECISION

NORMAL

. Press

ENTER

option, press the

when you are done, or

EDIT

CLEAR

Receiver

Options

GPS speed

averaging

The 941X’s capability over several of the unit’s GPS and DGPS navigation functions.

When not using Differential GPS, you may notice that Speed-OverGround readings obtained from the GPS satellite system ar e slightly erratic, varying by up to several knots. The 941X’s function can often improve the steadiness of these rea dings, at the expense of a slightly longer display reaction time when the speed changes.

The time over which your speed is averaged by the 941X may be selected with this function, with values between two and ten seconds available. Averaging may also be turned reaction time.

RECEIVER OPTIONS

OFF

provide you with advanced control

SPEED AVERAGING

completely for the quickest possible

A longer averaging time is useful at lower speeds, where the h ighest accuracy is required, such as when you want to trawl at a certain optimum speed. You will see a slower-changing, more steady display of your speed, with a high degree of accuracy. Shorter averaging times, however, will give you a quicker-changing display of your speed, but with less accuracy.

Rev. D 8 — Customizing the 941X

8 — Customizing the 941X Page 87

8 — Customizing the 941X8 — Customizing the 941X

Page 96

To change the speed averaging value:

1. Move the cursor arrow in front of the option and press the

2. Use the up/down cursor keys to select an averaging time of two to 10 seconds—or OFF.

EDIT

menu key.

GPS SPEED AVERAGING

beacon

frequency/

beacon baud

rate

3. Press

You may change the speed averaging value at any time without affecting other 941X navigation functions.

(RECEIVER OPTIONS)

(RECEIVER OPTIONS)(RECEIVER OPTI ONS) If your 941X either contains an internal beacon receiver or is interfaced

to an external Northstar beacon receiver, you can set the 941X to control the beacon receiver aut omatically or c ontrol it manua lly yourself. U nder automatic control, the receiver scans for nearby beacon transmitters and uses the one having the best signal for your area. It finds the beac on frequency and data transfer (baud) rate, then receives data fully automatically.

If you prefer, you can set the beacon frequency and baud rate manually to tune in a particular beacon transmitter. (Refer to the “manual mode” operation of the internal beacon receiver on page 75.) For normal opera tion, it is recommended that these controls be set to AUTO.

The beacon frequency can be set to any value between 283.5kHz and 325kHz. The baud rate should be set to AUTO, but can be manually set, if necessary, to any of the four standar d rates: 25bps, 50b ps, 100 bps or 200 bps.

ENTER

previous setting.

to make the change, or

CLEAR

to leave the value at it

(RECEIVER OPTIONS)

dgps operation

Page 88 8 — Customizing the 941X

(RECEIVER OPTIONS)(RECEIVER OPTI ONS) This option allows you to enable or disable use of differential corrections

while navigating in areas where no DGPS signals are availa ble (several hundred miles from the nearest transmitter, for inst ance). When set to

DISABLED

from an internal or external source. For normal operation, it is recommended that this setting be left at the factory default of

, the 941X ignores the use of DGPS signals, wh ether they are

8 — Customizing the 941X Rev. D

8 — Customizing the 941X8 — Customizing the 941X

ENABLED

Page 97

GPS data

timeout

(RECEIVER OPTIONS)

(RECEIVER OPTIONS)(RECEIVER OPTI ONS) This setting determines how long the 941X will continue to use existing

DGPS corrections if no new corrections are being received (due to bad weather, extreme distance from beacon, etc.). If this time period elapses with no new DGPS data received, the 941X reverts to standard GPS navigation, and displays

Under normal operating conditions, this “time-out” should be set to one or two minutes to guarantee the highest accuracy. In poor weather conditions, this value can be increased to a maximum of five minutes to ignore occasional outages in the beacon reception (if a minor loss of accuracy can be tolerated). The default setting is 60 seconds.

OLD CORRECTIONS

as the DGPS status.

To change the “age of correction” timeout, use the up/down cursor keys

Rev. D 8 — Customizing the 941X

to move the arrow at the left of the screen to

EDIT

Press onds to five minutes, in 30-second increments.

Press

, then use the cursor keys to choose any value from 30 sec-

A period of 30 seconds is, in many cases, too short and can lead to intermittent problems. Generally, one minute (the default value set at the factory) provides good navigation accuracy, and is best left unchanged.

ENTER

to make your selection, or

8 — Customizing the 941X Page 89

8 — Customizing the 941X8 — Customizing the 941X

NOTE

DGPS DATA TI ME OUT:

CLEAR

to leave it unchanged.

Page 98

lowest sat

elevation

After this “timeout” period elapses with no DGPS data having been received, the 941X will revert to navigating with normal GPS, the DGPS display indicator (shown at left) will be turned off, and the “DGPS lost” alarm will sound, if enabled (see “Alarms,” beginning on page 68 ). DGPS navigation will resume automa tically as soon as vali d correcti ons are r eceived again.

(RECEIVER OPTIONS)

(RECEIVER OPTIONS)(RECEIVER OPTI ONS)

It is recommended that this option be left at the factory default of 10°.

LOWEST SAT ELEVATION

The applications where th e 941X is tra cking all visi ble satellit es, regar dless of how low they are situated relative to the horizon. In those instances where high-precision fixes are necessary, the a dvanced user can modify this option to “hide” any low satellites, thereby preventing their use as sources of GPS position information, and avoiding potential errors.

If needed, this option is adjustable from 0° to 25°, in 5° increments.

NOTE

option is used primarily in technical

Port Setup

Options

Page 90 8 — Customizing the 941X

The 941X allows you to connect (or “interface”) directly with a variety of external devices, such as autopilots, radars, depth sounders, computers, etc.

Connection is made through any of three data transmission “ports” located on the back side of the 941X: two NMEA ports and one RS-232 port. Each is capable of operating independently, thereby giving you the flexibility of driving (or “talking to”) three separate devices simultaneously. The ports are also independently configurable to meet the specifications of most peripheral navigation equipment. This ensures a customized setup for virtually any NMEA 0183-compatible device. Once configured, the 941X will continuously send a stream of data to the device(s).

8 — Customizing the 941X Rev. D

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Page 99

Refer to “Programming the Output Ports,” on page 115, for detailed information on how to interface your 941X with other equipment.

Service Options

serial number

To view your 941X’s serial number and hardware specifications, press

STAR

the Press the screen:

(SERVICE INFORMATION)

(SERVICE INFORMATION)(SERVICE INFORMATION) In addition to being affixed to the back of the unit, your 941X’s serial

number is permanently programmed into memory at the factory. Serial numbers ending with the letter “D” indicate that the unit contains an internal DGPS beacon receiver. Be sure to have your 941X’s serial number and software version available (see below) whenever contacting, or corresponding with, your Northstar dealer or the factory.

key until the

SERVICE INFORM ATION

USER CU STOMIZATION

menu key to display the followi ng

screen is displayed.

Rev. D 8 — Customizing the 941X

8 — Customizing the 941X Page 91

8 — Customizing the 941X8 — Customizing the 941X

Page 100

main board

soft ver

beacon rx

soft ver

beacon rx

self test

(SERVICE INFORMATION)

(SERVICE INFORMATION)(SERVICE INFORMATION) This number indicates the revision level of your 941X’s operati ng soft-

ware program.

(SERVICE INFORMATION)

(SERVICE INFORMATION)(SERVICE INFORMATION) If your 941X has an internal beacon receiver installed, this line will con-

tain a number indicating the software revision of the beacon receiver. If none is installed, the line will be blank.

(SERVICE INFORMATION)

(SERVICE INFORMATION)(SERVICE INFORMATION) The 941X automatically self-tests the internal beacon receiver (if in-

stalled) each time the unit is powered up. If all test parameters are met, this field will say criterion, the message cause of the failure is an open or shorted antenna cable, which can be repaired in the field. If this is not the source of the failur e, return the 941X to the factory for service.

PASSED

FAILED

. If the beacon receiver fails in any of the test

will be displayed. In many cases, the

(SERVICE INFORMATION)

gps rx soft ver

gps rx self test

Page 92 8 — Customizing the 941X

(SERVICE INFORMATION)(SERVICE INFORMATION) This displays the software revision being used by your 941X’s main GPS

receiver. If these lines are blank, the GPS receiver has not been tested recently. Press the seconds for the test procedure to be completed. Once finished, the receiver’s revision number will be displayed, along with the message

PASSED

in the

8 — Customizing the 941X Rev. D

8 — Customizing the 941X8 — Customizing the 941X

TEST GPS RX

GPS RX SELF TEST

menu key and wait approximately 15

line at the bottom of the screen. If

Northstar 941X User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

WARRANTY

CONTENTS

Introducing the Northstar 941X

Introduction

Features

GPS features

Functions

GPS and DGPS

loran

Mounting

loran TDs

plotter functions

TideTrack™

Using the Controls

POWER Key

CONTRAST Key

SAVE/MOB Key

Function Keys

POSITION key

STEER k ey

STAR key

NAV LOG key

Menu Keys

Cursor Keys

Keypad

entering letters

alarm messages

Information windows

question windows

Basic Navigation

Positio n Plo tter

zooming

course restart

plotter options

Using GPS

time of day

datum

status summary

Using DGPS

satellite status

DGPS status

Using Loran

selecting loran

loran TDs

loran GRI

loran warnings

loran info

Entering Data

entering letters

avoidance area

Waypoint Lists

alpha list

saved list

avoid list

local list

route name

verifying entry

Saving a Route

route name

ending the route

coordinates

quick plot

The NAV LOG Function

ETA and ETE

pass status

restart

Other Special Functions

Alarms

alarm audio

anchor watch

arrive radius

dgps alarm

selecting a day

automatic mode

manual mode

Customizing the 941X