Garmin GPS 120XL User Manual

®

GPS 120XL

ZOOM

Marine

Navigator

Owner’s Manual

&

Reference

Software Version 2.0 or above
© 1997 GARMIN Corporation

1200 E. 151st Street, Olathe, KS USA 66062
Tel: [phone] or 800-800-1020
Fax: [phone]
Web Site Address: www.garmin.com

GARMIN (Europe) Ltd.
Unit 5,
The Quadrangle, Abbey Park Industrial Estate,
Romsey, SO51 9AQ, U.K.
Tel: [phone]
Fax: [phone]

GARMIN (Asia) Corp.
4th Fl., No. 1., Lane 45,
Pao-Hsing Road,
Hsin Tein,
Taiwan R.O.C.
Phone: [phone]
Fax: [phone]

All rights reserved. No part of this manual may be reproduced or transmitted in any
form or by any means, electronic or manual, including photocopying and recording, for
any purpose without the express written permission of GARMIN.

Information in this document is subject to change without notice. GARMIN reserves
the right to change or improve its products and to make changes in the content without
obligation to notify any person or organization of such changes or improvements.

GARMIN, Personal Navigator, AutoLocate,TracBack, and MultiTrac 8 are all trade­marks of GARMIN Corporation and may not be used without the expressed permission
of GARMIN.

July 1997 - Part #190-00136-00 Rev. B - Printed in Taiwan.

INTRODUCTION

GPS 120XL

OPERATOR’S

Overview

MANUAL

Welcome to the easiest-to-use fixed-mount GPS on the water!
The GPS 120XL represents GARMIN’s continuing commitment to provide
mariners with quality navigation information in a versatile, accurate and user­friendly design which will be useful for years to come. To get the most from
your new GPS unit, it is important that you take the time to read through the
operator’s manual to understand the operating features of the GPS 120XL.
The manual is organized into four sections for your convenience:

Introduction gives a quick overview of the manual and contains the
table of contents and glossary of navigation terms.

Getting Started takes you through step-by-step instructions to initialize
the receiver for first-time use and introduces you to the basic features of the
unit with a quick-start orientation to the GPS 120XL. This section has been
designed to acquaint you with the unit and provide a basic working knowl­edge necessary to use the unit in typical conditions.

Reference provides detailed explanations of the advanced features and
operations of the GPS 120XL in a topical format. This allows you to concen­trate on a specific topic quickly, without reading through entire sections of
text that you may not need.

The Appendix section contains installation instructions and items with
multiple listings, such as: map datams, time offsets, and the index.

Packing List

Before getting started with your GPS receiver, check to see that your
GARMIN GPS 120XL package contains the following items. If you are miss­ing any parts, please contact your dealer immediately.

Standard Package:

• GPS 120XL Unit • Mounting Bracket with knobs

• External Antenna with 30’ cable • Owner’s Manual

• Power/Data Cable • Quick Reference Card

See your GARMIN dealer for accessories, including our PC kit.

Thanks for choosing the GARMIN GPS 120XL. We hope it will help you
meet all of your navigation needs.

i

INTRODUCTION

Caution

The GPS system is operated by the government of the United States,
which is solely responsible for its accuracy and maintenance. The system is
subject to changes which could affect the accuracy and performance of all
GPS equipment. Although the GPS 120XL is a precision electronic
NAVigation AID (NAVAID), any NAVAID can be misused or misinterpreted
and, therefore, become unsafe.

Use the GPS 120XL at your own risk. To reduce the risk of unsafe
operation, carefully review and understand all aspects of this Operator’s
Manual and thoroughly practice operation using the simulator mode prior to
actual use. When in actual use, carefully compare indications from the GPS
120XL to all available navigation sources including the information from
other NAVAIDs, visual sightings, maps, etc. For safety, always resolve any dis­crepancies before continuing navigation.

NOTE: This device meets requirements for Part 15 of the FCC limits for
Class B digital devices for home or office use. It has been tested for compli­ance with all necessary FCC standards. This equipment generates, uses, and
can radiate radio frequency energy and, if not installed and used in accor­dance with the instructions, may cause harmful interference to radio commu­nications. However, there is no guarantee that interference will not occur in a
particular installation. If this equipment does cause harmful interference to
other equipment, which can be determined by turning the equipment off and
on, the user is encouraged to try and correct the interference by relocating the
equipment or connecting the equipment to a different circuit than the affected
equipment. Consult an authorized dealer or other qualified service technician
for additional help if these remedies do not correct the problem. Operation is
subject to the following conditions: (1) This device cannot cause harmful
interference, and (2) this device must accept any interference received,
including interference that may cause undesired operation. The GPS 120XL
does not contain any user-serviceable parts. Repairs should only be made by
an authorized service center. Unauthorized repairs or modifications could
void your warranty and your authority to operate this device under Part 15
regulations.

ii

INTRODUCTION

Table of

Contents

SECTION ONE Introduction

Glossary/Navigation Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-4

SECTION TWO Getting Started

Turning On and Initializing the Receiver . . . . . . . . . . . . . . . . . . . . . .5-7

Primary Page Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-9

Marking a Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10-11

Position and Map Page Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . .11-12

Going To a Waypoint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

Using the Highway Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

Cancelling a GOTO and Clearing Maps . . . . . . . . . . . . . . . . . . . . . . .15

SECTION THREE Reference

Satellite Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16-17

Position Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18

Marking, Saving, and Using Waypoints . . . . . . . . . . . . . . . . . . . . .19-26

TracBack Navigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27-28

Creating and Using Routes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29-34

Using the Compass and Highway Navigation Pages . . . . . . . . . . . .35-37

Map Plotting, Zooming, and Cursor Movement . . . . . . . . . . . . . . .38-40

Menu Page and Distance/Sun Calculation . . . . . . . . . . . . . . . . . . . . . .41

Track Log Setup and TracBack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42

Interface Setup and DGPS Interface . . . . . . . . . . . . . . . . . . . . . . . .43-45

System Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46-47

Navigation Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48-50

Map Page Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51-52

Alarms Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53

Navigation Simulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54

Appendix A––Unit and Antenna Installation . . . . . . . . . . . . . . . . .55-57

Appendix B—Specifications and Wiring . . . . . . . . . . . . . . . . . . . .58-59

Appendix C—Messages/Time Offsets . . . . . . . . . . . . . . . . . . . . . . .60-61

Appendix D—Map Datums . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62-64

Appendix E—Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65-66

1

INTRODUCTION

Glossary

The GPS 120XL is a powerful navigation tool that can guide you anywhere
in the world. To better understand its operation and capabilities, it may be
helpful to review the basic terms and concepts briefly explained below.

Other navigation and GPS definitions used in the manual are defined in the
appropriate reference sections of the manual.

Almanac Data

Satellite constellation information (including location and health of satellites)
that is transmitted to your receiver from every GPS satellite. Almanac data must
be acquired before GPS navigation can begin.

Bearing

The compass direction from your position to a destination.

Course Made Good (CMG)

The bearing from the “active from” position (your starting point) to your

present position.

Crosstrack Error (XTE)

The distance you are off a desired course in either direction.

Desired Track (DTK)

The compass course between the “from” and “to” waypoints.

Differential GPS (DGPS)

An extension of the GPS system that uses land-based radio beacons to trans­mit position corrections to GPS receivers.

Estimated Time of Arrival (ETA)

The time of day of your arrival at a destination.

Estimated Time Enroute (ETE)

The time left to your destination at your present speed.

2

INTRODUCTION

Glossary

Grid

Coordinate system that projects the earth on a flat surface, using square
zones for position measurements. UTM/UPS and Maidenhead formats are
grid systems.

Ground Speed

The velocity you are traveling relative to a ground position.

Latitude

The north/south measurement of position perpendicular to the earth’s
polar axis.

Longitude

An east/west measurement of position in relation to the Prime Meridian,

an imaginary circle that passes through the north and south poles.

Navigation

The process of traveling from one place to another and knowing where

you are in relation to your desired course.

Position

An exact, unique location based on a geographic coordinate system.

Track (TRK)

The direction of movement relative to a ground position.

Universal Transverse Mercator (UTM)

A grid coordinate system that projects global sections onto a flat surface to

measure position in specific zones.

Velocity Made Good (VMG)

The speed you are traveling in the direction of the destination.

Waypoint

A specific location saved in the receiver’s memory.

3

INTRODUCTION

NORTH

“ACTIVE FROM”

WAYPOINT

NORTH

DTK

CROSSTRACK ERROR

BRG

TRK

GROUND SPEED

DISTANCE

“ACTIVE TO”

WAYPOINT

“ACTIVE LEG”

Navigation

Basics

The GPS 120XL provides steering guidance and navi­gation information using degrees, a measurement measured
in a clockwise direction from a north reference. North is
described as 000º, east as 090º, south as 180º, and west as
270º. The diagram and compass rose below provide a graphic
illustration of the navigation terms used by the GPS 120XL.
More information on basic navigation and GPS are available
at your local library or bookstore.

4

Getting Started with your GPS

Welcome to the exciting world of GARMIN GPS!
The GPS 120XL represents GARMIN’s continuing com­mitment to provide marine users with quality naviga­tion information in a versatile, user-friendly design they
will enjoy for years to come. To get the most out of
your GPS receiver, be sure to read through the initial­ization and Getting Started sections of this manual, and
refer to the reference section for complete details on
the GPS 120XL’s advanced features.

Initializing Your GPS for First-Time Use

The first time you power up your new GPS 120XL
is an important step in getting the best possible future
GPS performance.

Because a GPS receiver can only receive signals
from satellites above the horizon, it needs to know
what satellites to look for at any given time. By using
an almanac (a timetable of satellite numbers and their
orbits) stored in the receiver’s memory, the GPS 120XL
can determine the distance and position of any GPS
satellite and then use this information to determine
your position.

To obtain this almanac data, your GPS receiver
needs to be initialized -- or given the opportunity to
“find itself”-- the very first time it is turned on. Once
you have initialized the unit, the GPS 120XL will com­pute future fixes more rapidly, usually in a few
minutes.

Remember that initializing the unit is only neces­sary under the following conditions:

• First-time use from the factory

• If the receiver has been moved over 500 miles
from the last calculated position with power off

• If the receiver’s memory has been cleared and all
stored data has been lost

GETTING

STARTED

Initialization

Welcome Page

The welcome page will
appear as soon as the GPS
120XL is turned on and
remain while the unit con­ducts a brief self-test.

5

GETTING

STARTED

Initialization

The EZinit prompt will
automatically appear if the
receiver needs to be initial­ized. The prompt may also
appear during normal use if
the antenna is shaded.

Initializing the Receiver

The receiver is shipped from the factory in
AutoLocate™ mode, which enables the GPS 120XL to
determine its location anywhere in the world. To speed
up the initialization process, we recommend using the
graphic initialization described below, which will usual­ly provide a fix in 7.5 to 15 minutes.

Before you initialize, make sure your GPS 120XL
unit and antenna have been correctly installed on your
boat according to the instructions in Appendix A.

To turn the GPS 120XL on:

1. Press and hold Puntil the receiver turns on.

The welcome page will be displayed while the unit
conducts a self test.

Once testing is complete, the welcome page will be
replaced by the Satellite Page, with the EZinit prompt
ready for you to select one of two initialization
methods:

•Select Country––allows you to initialize the
receiver by selecting your present position from a
list of countries in the GPS 120XL’s internal data­base. This usually provides a position fix in a few
minutes.

TM

•Autolocate

––allows the GPS 120XL to initialize
itself and calculate a position fix without knowing
your present position. This usually provides a posi­tion fix in 7.5-15 minutes.

If the EZinit prompt has not automatically
appeared on the Satellite Page:

Use the arrow keypad to
highlight the country,
region or state of your pre­sent position from the list
and press ENTER. If the
country is not listed, select
the closest country instead.

6

1. Press the Fkey.

Note: If the EZinit prompt ever appears after you
have initialized the receiver (due to the antenna’s view
of satellites being obstructed by trees, etc.), highlight
the ‘no re-init’ selection with the arrow keypad and
press ENTER.

To initialize the receiver:

1. If the ‘country’ option is not highlighted, press the
key repeatedly to move the field highlight to the ‘coun­try’ option.

2. Press the

F

key.

D

Initializing the Receiver (cont)

3. Use theDkey to scroll through the list options until
the country of your present position appears.

4. Use the

U

you’re in. If the country you’re in is not listed, select
another country within 500 miles of your present
position.

key to highlight the country/state/region

GETTING

STARTED

Initialization

5. Press

F

to finish.

The GPS 120XL will now begin searching for the
appropriate satellites for your location and should
acquire a position within 3-5 minutes. You can verify
that you have acquired a position by watching the
Satellite Page transition to the Position Page (provided
you haven’t pressed any other buttons) or by looking for
a ‘2D NAV’ or ‘3D NAV’ status at the top left corner of
the Satellite Page.

Initialization Troubleshooting

If you have trouble initializing the receiver or
acquiring a position, check the following:

• Does the antenna have a clear view of the sky?

If there are large buildings or mountains nearby, or

if there is heavy tree cover, the receiver may not be

receiving enough satellite signals to calculate a

position.

• Have you selected the right country/state/region
from the EZinit list?

Check for the correct approximate lat/lon on the
Position Page, or reselect the appropriate country
from the list to restart the initialization.

• Have you moved more than 500 miles from the
last calculated position with the receiver off?

Reinitialize the receiver, selecting the country/state/
region of your new location from the EZinit list.

Your unit should now be initialized. If you want to
complete the Getting Started Tour at another time, you
may now turn the GPS 120XL off (see below) or you
may continue.

To turn the GPS 120XL off:

1. Press and hold Pfor approximately three seconds
until the receiver turns off.

The GPS 120XL’s Satellite
Page will help you deter­mine which satellites are in
view and whether or not
any satellites are being
“shaded” or blocked from
the receiver’s antenna.

By monitoring the signal
strength bars at the bottom
of the page and the sky view,
you’ll be able to see how
moving to another area with
a clearer view of the sky will
improve satellite reception
and speed up signal
acquisition.

7

GETTING

STARTED

Primary Pages

Satellite Page

The Satellite Page will
allow you to monitor satel­lite signal reception and
strength.

Primary Pages

Before we start the tour, let’s briefly look at the five
primary information pages used for the GPS 120XL.
Note: Switch between pages by pressing either the
or Jkeys.

Q

J

Q

Satellite Page

The Satellite Page shows satellite positions and
signal strength. Satellite positions are displayed using
two circles and a center point. The outer circle shows
satellites on level with the horizon; the inner circle is
45º above the horizon; and the center point represents
satellites directly overhead. Knowing satellite positions
will show you the direction of any blocked signals.

The bottom of the page contains a row of signal
strength bars corresponding to each satellite being used.

Position Page

The Position Page shows you where you are, what
direction you’re heading and how fast you’re going.

The top of the page contains a compass tape which
is a graphic representation of your heading. Your track
and speed are indicated immediately below.

Position Page

8

The graphic compass tape reflects your head-

!

#

ing only while you are moving.

The rest of the page shows your current position in
three dimensions: latitude, longitude and altitude. A
trip odometer and 12/24 hour clock are also provided.

Map Page

The Map Page acts as a window. It allows you to
view your position, the “path” you have traveled over,
and nearby waypoints.

A diamond icon in the center of the screen repre­sents your current position. As you move, you will see
a thin line-- called a track log-- appear along the path
you have just covered. Names of stored waypoints can
also be shown on the map.

The bottom corners of the screen will always dis­play your current track and speed. When going to a
waypoint, highlighting an on-screen waypoint, or using
the panning target crosshair, the corresponding dis­tance and bearing are shown at the top corners of the
screen.

GETTING

STARTED

Map, Navigation

& Menu Pages

Navigation Page

A navigation page gives you steering guidance
when going to a waypoint. The GPS 120XL has two
navigation page choices: the Highway Page and the
Compass Page. The Highway Page is the default and
will be briefly explained here. The Compass Page is
covered on pages 35 and 37.

The Highway Page uses a graphic highway to
show your movement in relation to your desired
course. The upper section shows bearing and distance
to the waypoint and your current track and speed. The
middle portion contains the actual highway. The high­way indicates the crosstrack error, or distance and
direction, your are off-course from your waypoint.
Always turn in the direction the highway is pointing.
For example, if the highway points straight up, no turn
is required. If the highway points right, you need to
turn right until the highway points straight up. The
remainder of the page contains the estimated time
enroute (ETE) and your velocity made good (VMG).

Menu Page

The last primary page is the Menu Page. The
Menu Page gives you access to the GPS 120XL’s way­point management, route, track log, and setup features
through a list of submenus.

Map Page

Shows your progress on a
moving track plotter and
get a bird’s-eye-view of sur­rounding waypoints with
the Map Page.

Highway Page

With the Highway Page,
you will get graphic steer­ing guidance in navigating
a route or to a single way­point.

9

GETTING

STARTED

Marking A

Position

The simulator mode will
allow you to practice navi­gation and become familiar
with the GPS 120XL with­out leaving your slip.

Getting Started Tour

Now that your GPS receiver has been initialized and
you are familiar with the primary pages, it’s time to take
a tour. This is a live tour and is to be conducted with
your unit installed and with the boat in the water. The
tour will take you through the receiver’s basic features
and functions as you move about on the water and
assumes that the GPS 120XL is turned on, initialized,
and that you have not changed any of the factory set­tings (units of measure, selectable fields, etc.). If these
settings have been changed, the pictures and descrip­tions in this manual may not match what you see on
your screen.

Navigation Simulator

If you are not able to take the Getting Started Tour
with your boat in the water, you may use the built-in
navigation simulator to practice using the GPS 120XL.
To use the simulator, see page 54.

Marking a Waypoint

To begin the tour, let’s take the position you have
acquired (either by just initializing the unit or by having
turned the unit on) and mark it as a waypoint for future
reference.

To save a waypoint with the
default three-digit name,
simply press the MARK key
followed by the ENTER key.
The GPS 120XL will then
return to the page previous­ly displayed.

10

1. Press the Mkey to capture and hold your position.

To mark a position, you must have obtained a

!

#

2D or 3D fix, or have the receiver in simulator
mode. If you try to mark a position without a
position fix, you will be alerted with a ‘No GPS
Position’ message.

The mark position page will appear, showing the
captured position and a default 3-digit waypoint name.
Let’s change the default name to something a little more
meaningful, like ‘DOCK’.

1. Press theUkey twice to move the field highlight
from the ‘save’ field to the name field.

GETTING

STARTED

Marking A

Position

2. Press
name.

3. Press and hold the
alphabet until the letter ‘D’ appears.

4. Press the
to the next character space.

5. Repeat steps 3 and 4 until the word ‘DOCK’ is dis­played.

6. Press

7. Press the
the ‘save’ field.

8. Press the
the position as a waypoint named ‘DOCK’.

and Lto clear the default waypoint

F

U

key to scroll through the

R

key once to move the character highlight

to complete entry of the name.

F

key once to return the field highlight to

D

key to confirm that you want to save

F

The mark position page will now be replaced by
the Position Page (or whatever page was displayed
prior to pressing the

key). The ‘DOCK’ waypoint

M

is now stored in the GPS 120XL’s memory, and will
remain there until you manually remove it or clear the
receiver’s memory. For more on waypoint management,
see pages 19-25.

Using the Position and Map Pages

Now that you’ve marked a position, let’s see how
the Position and Map Pages can be used to monitor
your progress as you head out in to the open water.

The arrow keypad is used
for all data entry. Use the
UP and DOWN keys to
select letters, numbers, or
menu options, and use the
LEFT and RIGHT keys to
move the cursor forward or
backward along the line.

Position Page

As always, ensure your primary focus is on

!

#

boating traffic and monitor the GPS120XL
briefly when operating your boat.

11

GETTING

STARTED

Position & Map

Pages

The Map Page displays
your present position as a
diamond icon and provides
real-time graphic “bread­crumb” display of your
track right on the screen.

Using the Position and Map Pages (continued)

As you head out, the Position Page will help you

monitor your movement.

Graphic

Track Over

Ground

Tr i p

Odometer

Position
Display

Compass Tape

Current Speed

Altitude

12/24 Hour

Time

The direction you are moving (your track) and your
speed are displayed on the upper part of the page, just
below the graphic compass tape. The latitude, longitude
and approximate altitude of your position, along with a
resettable trip odometer, are continuously displayed in
the middle of the page, and the time of day is displayed
below.

Now let’s change the display to the Map Page and
watch the track log of our tour:

1. Press the Jkey to change from the Position Page
to the Map Page.

To get a larger view of the Map Page, lets change the

the zoom scale from .2 (default) to 1.0 nautical mile.

To select a larger zoom scale on the Map Page:

The moving map’s default
screen orientation is track
up orientation. “Track up”
means that your current
direction of travel is always
up (or towards the top of)
the screen. It can also be set
for north up, or desired
track orientation through
the map setup page.

12

1. Press the Hkey until ‘1.0 n.m. zoom scale’ appears.

Your current position is shown as the diamond in
the middle of the screen. The dark circle below the dia­mond represents the position you created, with the line
between the two showing your track.

1. Once you have reached an area that allows for gener­al changes in direction without interfering in the pas­sage of other boats, mark your current position again
and name this waypoint “CHANNL”. (See ‘Marking a
Waypoint’ on pages 10-11)

2. Next, make a moderate turn in any direction safe for
navigation and proceed for another 3 minutes.

Going To a Waypoint

Once you’ve stored the “CHANNL” waypoint in
memory, you can use the GPS 120XL to guide you to it
by performing a simple GOTO. A GOTO is nothing
more than a straight-line course from your present
position to the destination you’ve selected.

Use caution when navigating. A “straight-line”

!

#

course reflects the shortest distance to a waypoint,

and does not navigate around obstructions, such

as land or buoys, etc.

Now that you have moved away from ‘CHANNL’
for three minutes, let’s try navigating back to it.

To select a GOTO destination:

GETTING

STARTED

Going To A

Waypoint

1. Press the Gkey.

2. The GOTO waypoint page will appear, displaying all
the waypoints in memory in alphabetical order.

3. Use

U

or Dto highlight the ‘CHANNL’ waypoint.

4. Press the
gate to the displayed waypoint. The Highway Page
(default) will appear.

Bearing to

Waypoint

Destination

Waypoint

“Finish Line”

key to confirm that you want to navi-

F

Distance to

Destination Waypoint

CDI Scale

Waypoint

The GPS 120XL’s Highway Page provides graphic
steering guidance to a destination, with an emphasis on
a straight-line course to the desired waypoint and the
distance and direction you are off course. The bearing
and distance to a waypoint, along with your current
track and speed are displayed at the top of the screen,
with your estimated time enroute (ETE) and velocity
made good (VMG), or the speed you are approaching
your destination, shown at the bottom.

The GOTO waypoint page
allows you to select your
destination from a list of all
available waypoints in the
GPS 120XL’s memory.

Once a GOTO is activated,
the GPS 120XL will provid­ed steering guidance until
the GOTO is cancelled. To
cancel a GOTO, highlight
the cancel prompt at the
bottom of the page and
press ENTER.

13

GETTING

STARTED

Using the Highway Page (continued)

Using The

Highway Page

The 120XL will also provide
steering guidance with a
graphic compass page.

To change the display from
the highway page, press
ENTER twice.

Current Track

Position

Diamond

Estimated

Time of
Arrival

Pointer to Waypoint

Current Speed

Velocity Made

Good

As you head toward your destination, the middle
section of the screen provides visual guidance to your
waypoint on a moving graphic “highway”. The moving
arrow just below the course deviation scale always
points to your selected waypoint relative to the direc­tion you are moving.

Your present position is represented by the diamond
in the center of the course deviation scale. The line
down the middle of the highway represents your
desired track. As you navigate toward a waypoint, the
highway will actually move, indicating the direction
you’re off course, relative to the position diamond on
the CDI scale. To stay on course, simply steer toward
the center of the highway.

While navigating, you may decide to use the
Compass Page (see picture above left) instead of the
Highway Page.

Once you are one minute
from the destination (based
on your present speed and
course), an arrival message
will appear on the message
page.

14

To select the Compass Page:

1. While viewing the Highway Page press F, twice.

The Compass Page will now become the displayed
navigation page. This page provides a directional point­er to your destination, by using a rotating compass dis­play to show direction of travel. It provides better steer­ing guidance at slower speeds for travel with many
directional changes.

To switch back to the Highway Page, press ENTER
twice.

Cancelling a GOTO

If you decide to stop navigating to the active way-

point, all you have to do is cancel the GOTO.

To cancel an active GOTO:

1. Press the Gkey.

2. Use the arrow keypad to move the field highlight to
the ‘CANCEL GOTO?’ prompt at the bottom of the page
and press

F

.

Clearing a Cluttered Map Display

After you’ve used the GPS 120XL for a few trips,
you may find that your map display has become a bit
messy from keeping track of your every move. For
practice, let’s clean up the screen by clearing the track
log (the plot points left on the Map Page) we’ve just
created during the Getting Started Tour.

1. Press Jor Quntil the Menu Page appears.

2. Use the

D

‘TRACK LOG’ option.

3. Press

4. Press the
option. The clear log confirmation page will appear.

key to move the field highlight to the

to access the track log page.

F

U

key twice to highlight the ‘CLEAR LOG?’

GETTING

STARTED

Cancelling A

GOTO &

Clearing Maps

Highlight the ‘CLEAR
LOG?’ prompt and press
ENTER to clear the track
log. Once all 1024 points
are used, the oldest point
will be continuously deleted
to make room for the latest
track log point.

5. Use the

6. Press

L

key to highlight the ‘Yes’ prompt.

to finish.

F

Turning the Receiver Off

You’ve now gone through the basic operation of
your new GPS receiver and probably know a little more
than you think about how it works. We encourage you
to experiment with the GPS 120XL until it becomes an
extension of your own navigation skills. If you
encounter any problems using the unit or want to take
advantage of the GPS 120XL’s more advanced features,
refer to the reference section.

To turn the GPS 120XL off:

1. Press and hold the Pkey for 3 seconds.

Holding the POWER key
for three seconds ensures
against accidental shut-off
by accidentally pressing the
button.

15

REFERENCE

Satellite Page

Overview

As soon as a satellite has
been found and the GPS
120XL is acquiring position
data, the satellite number
will turn to normal presen­tation and a hollow bar will
appear.

Satellites being tracked but
blocked from use (03,17)
will be displayed in reverse
video, with the correspond­ing signal strength bar hol­low.

Satellite Page

Status

Satellite

Numbers

Satellite

Sky View

Satellite

Sky View

The Satellite Page displays the status of various
receiver functions. The status information will help you
understand what the GPS 120XL is doing at any given
time, and will tell you whether or not the receiver has
calculated a position fix.

Sky View and Signal Strength Bars

The sky view and signal strength bars give you an
indication of what satellites are visible to the receiver,
whether or not they are being used to calculate a posi­tion fix, and the signal quality. The sky view in the cen­ter of the page shows a bird’s-eye view of the position of
each satellite relative to the receiver’s last known posi­tion. The outer circle represents the horizon (north up);
the inner circle is 45º above the horizon; and the center
point is a position directly overhead.

When the receiver is looking for a particular satel­lite, the corresponding signal strength bar will be blank
and the sky view indicator will remain highlighted in
reverse video. Once the receiver has found the satellite,
a hollow signal strength bar will appear, indicating that
the satellite has been found and the receiver is collect­ing data from it. The satellite number in the sky view
will also change from reverse video to normal presenta­tion. As soon as the GPS 120XL has collected the neces­sary data to use the satellite for positioning, the hollow
bar will become solid.

16

Receiver Status and EPE

Receiver status is indicated at the top left of the
screen, with the current horizontal accuracy (estimated
position error, in feet or meters) at the top right. The
status will show one of the following conditions:

Searching— the GPS 120XL is looking for any

available satellites in view.

TM

AutoLocate

— the GPS 120XL is initializing and

collecting new almanac data. This process can take

7.5 to 15 minutes.

Acquiring— the receiver is collecting data from

available satellites, but has not collected enough

data to calculate a 2D fix.

2D Nav (2D Navigation)— at least three satellites

with good geometry have been locked onto and a

2-dimensional position fix (latitude and longitude)

is being calculated. ‘2D Diff’ will appear when you

are receiving DGPS corrections in 2D mode.

3D Nav (3D Navigation)— at least four satellites

with good geometry have been locked onto, and

your position is now being calculated in latitude,

longitude and altitude. ‘3D Diff’ will appear when

you are receiving DGPS corrections in 3D mode.

Poor CVG (Poor GPS Coverage)— the receiver is

no longer tracking enough satellites for a 2D or 3D

fix.

Not Usable— the receiver is unusable, possibly

due to incorrect initialization or abnormal satellite

conditions. Turn the unit off and back on to reset.

SIM (Simulating Navigation)— the receiver is in

simulator mode.

REFERENCE

Receiver Status

& EZinit

A ‘POOR CVRG’ status
will appear on the Satellite
Page if the receiver has lost
the satellites required to
compute a fix. Make sure
the external antenna is not
covered and is connected to
the GPS 120XL.

EZinit Option Prompt

The Satellite Page also provides access to the GPS
120XL’s initialization menu, the EZinit prompt. The
EZinit prompt will appear automatically the first time
the unit is turned from the factory, after 10 minutes of
unsuccessful satellite acquisition, or if you push the
ENTER key while viewing the Satellite Page with the
unit in searching, AutoLocate, acquiring, simulator, or
poor coverage modes. (See pages 6-7 for more on
EZinit.)

If you travel more that 500
miles with the receiver off,
reinitialize the unit to your
new position by using the
EZinit feature. To access
EZinit, press ENTER from
the Satellite Page before any
satellites are acquired.

17

REFERENCE

Backlighting &

Position Page

The speed and track dis­played on the Position Page
may fluxuate at slow speeds
(or when you’re standing
still) because of position
errors caused by Selective
Availability.

Screen Backlighting

The GPS 120XL features three levels of backlighting.
Activate the backlight by pressing the POWER key
briefly. Each press of the button advances the backlight­ing to the next level and then turns it off. Backlighting
will remain on until turned off. Note: a bulb icon will
appear on the Satellite Page when backlighting is on.

Position Page

The GPS 120XL’s Position Page shows you where
you are, the direction you are heading, and your speed,
and is most useful when you are traveling without an
active destination waypoint. A compass tape at the top
of the page displays your cardinal heading (while mov­ing), with current track and speed over the ground indi­cated below. The rest of the page shows your present
position in three dimensions (latitude, longitude and
altitude). The units of measure for speed, distance, posi­tion and altitude are all user-selectable through the nav­igation setup menu (see pages 48-50). The 12/24 hour
clock and time offset options are available from the sys­tem setup menu (see page 47).

Trip Odometer

The Position Page also features a resettable trip
odometer to measure your total distance traveled.

To reset the trip odometer:

To reset the trip odometer,
highlight the trip field and
press ENTER. Use the
LEFT arrow key to clear the
distance field, and press
ENTER to confirm.

18

1. Press the Dkey until the trip field is highlighted.

2. Press

3. Press

F

F

,

followed by L.

to finish.

Altitude Display

When the GPS 120XL is acquiring satellites or navi­gating in the 2D mode, the last known altitude will be
used to compute your position. If the altitude shown is
off by several hundred feet, you can manually enter
your altitude for greater accuracy. Note that GPS alti­tudes can fluxuate due to errors.

1. Press the Dkey until the altitude field is highlighted
and press

2. Use the arrow keypad to enter the altitude and press

.

F

F

.