NASA Marine Clipper User Manual

DESIGNED AND
MANUFACTURED
IN ENGLAND

CLIPPER GPS

3D

Speed over ground

Track

Distance to Waypoint Bearing

LIGHT DEST. STEER POSN.

RoHS

2002/95/EC

CLIPPER

GPS

REPEATER

CONTENTS PAGE

INTRODUCTION

INSTALLING THE DISPLAY

INSTALLING DIAGRAMS

GETTING OPERATIONAL

USING THE REPEATER

USING THE ROADWAY DISPLAY

ROADWAY DISPLAYS

TECHNICAL INFORMATION

TROUBLE SHOOTING

Page8 &Inside back cover

1

1

2-3

2

4

5

6

7

INTRODUCTION

The Clipper GPS Repeater is supplied with 10 metres of cable, a 3
way terminal block, and a 12 Volt power cable. The unit will repeat
the data sent by any GPS repeater set up to send NMEA 0183
output sentances RMB and RMC at 4800 baud.

INSTALLING THE DISPLAY

Select a convenient position for the display on a panel or bulk­head. The site must be flat and the cavity behind the panel must
remain dry at all times. (The cable entry is deliberately not sealed to
ensure adequate ventilation. This prevents misting of the display).

Cut a hole in the panel 67mm high and 87mm wide. Bring the
wiring through the hole in the panel and pass the 10 metre cable
through the hole.

Unscrew and remove the two wing nuts from the rear of the
instrument and remove the stainless steel clamping bracket. Fit the
“O” ring seal into the groove in the panel mounting face of the
instrument. Ensure that it is correctly lying in its groove before fitting
the instrument to the panel, which provides the watertight seal for
the display.

Fit the instrument into the panel, fit the stainless clamp over the
studs, fit and tighten the two wing nuts finger tight only.
It is important that the O-ring rubber seal makes good contact with
the panel to prevent water getting behind the unit and entering the
cavity behind the panel.

It is good practice to run the cables vertically downwards from the
unit, even if they later have to rise to connect to the vessel's
supplies. Doing so prevents any water that might get onto the
cables from running back along the cables and into the unit.

1

Figure 1

GPS

RECEIVER

NMEA OUTPUT or
NMEA OUTPUT (+ve ) wire

Negative Supply W

ire

If it exist, its usally labelled NMEA OUTPUT (-ve)
or NMEA OUTPUT (REF)

If not, then the reference is internally connected to ground,
and can be ingnored

Uncoil the cable and install it on a convenient run to the GPS receiver
position.
Refer to Figures 1 and 2. to connect the GPS receiver to the GPS and
vessels supply.

GETTING OPERATIONAL

Switch on the GPS receiver. Refer to the manufacturer's handbook, and
set up the unit to send NMEA version 2.0 (or later version) at 4800 Baud.
When the GPS Repeater is powered on, the words Clipper GPS appear
momentarily on the screen. Note that the words are shown in a mixture
of Upper case (capitals) and lower case characters. This is because the
numerical display is also used to display text.

2

DEST. POSN.STEERLIGHT

Blue

Silver/Black

Figure 2

Red

+ve -ve

12 Volt SUPPLY

The International Seven-bar Substitution Character Set
(ISBSCS, usually shortened to ISCS) is used to represent the Upper-case
alpha-numeric characters used by most GPS receivers, as shown below.

A B C D E F G H I J K L M N O P Q R

S T U V W X Y Z 0 1 2 3 4 5 6 7 8 9 -

3

On some GPS receivers, no NMEA output is sent until lock onto the
satellites is achieved. If so, the Repeater displays the message “No
GPS Signal” as a warning. When the GPS Receiver has acquired
lock, the current position (Latitude and Longitude) will be displayed
on the Repeater.

Regardless of the settings on the GPS Receiver, the repeater always
displays distances in Nautical miles, speeds in knots, and all
bearings in magnetic. Latitude and Longitude is shown in degrees,
minutes and tenths, hundredths and thousnds of a minute.

USING THE REPEATER

Press POSN. at any time, and the repeater will display the current
position (Lat and Long) after a brief pause while it collects the fresh
NMEA data from the receiver. Unless a waypoint is selected on the
receiver, this is usually all the data available to the repeater.

Select a waypoint ( a destination) on the GPS receiver and press
STEER. The repeater will show the Speed over the ground (SOG)
screen. This screen shows the road, the speed over the ground (the
course made good), track, and distance and bearing to the
waypoint.

A second press of STEER shows the cross-track error (CTE) screen.
This replaces the speed over ground with the Cross-track error, and
leaves the other values as before. Pressing STEER alternates
between the CTE and SOG screens.

Press DEST. to display the name of the next waypoint (which has
been entered into the GPS receiver) and the direction to steer to
reach it. If the destination is within 30º of astern, “Astern” is
displayed, with the roadway showing the best turn direction to
regain the desired waypoint.

Press LIGHT to switch the backlight on at low level, and again to
switch the backlight to full brightness. Another press switches the
backlight off again.

4

USING THE ROADWAY DISPLAY

The roadway display is available on the DEST and STEER screens
(CTE and COG).

Steering guidance is represented on the roadway display. The
display indicates the direction to steer to reach the destination
waypoint from the present position. It does not indicate cross-track
error from the track between the departure and destination
waypoints stored in the GPS receiver.

If the cross-track (CTE) is being displayed, the cross-track error
includes a Left (L) or Right (r) indication, which indicates the
direction to steer to rejoin the desired track between departure and
destination waypoints.

The roadway display always shows the best direction to turn, even
if the vessel is moving away from the destination waypoint (and see
above). If the vessel is going away from the destination, this is
shown by the large difference
between the bearing to waypoint (destination) and the Track.

The roadway displays are shown overleaf, for all track and bearing
differences.

5

“Ahead”

Track within 3º of bearing to destination

Steer left Steer right

(Track > 3º off bearing to destination)

Steer left Steer right

(Track > 6º off bearing to destination)

Steer left Steer right

(Track > 9º off bearing to destination)

Steer left Steer right

(Track > 12º off bearing to destination)

Steer left Steer right

(Track > 15º off bearing to destination)

6

TECHNICAL INFORMATION

The GPS Repeater offers full functionality only when the GPS receiver
is set up to send NMEA 2.0 (or later) messages at 4800 baud. NMEA
Message types RMB, RMC, and GSA are required to fulfil all the
repeater's functions.

The repeater always shows the status of the signals it is getting from
the GPS receiver. If no NMEA data are being received, a No GPS
Signal message is displayed.

Some GPS receivers send NMEA data before full satellite acquisition is
achieved, but others wait until full acquisition is achieved before
sending any data over the NMEA connection. If position (POSN.) is
requested, and none is available from the GPS, No GPS POSN. is
displayed. If no Cross-track Error or Speed over Ground information is
available, appropriate messages are shown.

The Repeater always displays magnetic bearings, using the magnetic
offset sent by the GPS receiver. If true bearings are wanted on the
Repeater, it is necessary to set the GPS Receiver to Magnetic, and set
the magnetic deviation manually to zero.

The cable to the Repeater has two wires, Red and Blue, and an outer
screen. The screen is negative, and the red wire is connected to +12
Volts. The Blue wire carries the NMEA data from the GPS Receiver. The
cable can be shortened or extended up to 20 metres if desired.

Supply voltage: 8-16Volts D.C.
Current 3 mA (backlight Off)

7

TROUBLE SHOOTING

PROBLEM LIKELY CAUSE REMEDY

Repeater is
totally dead

Repeater
reports “NO
GPS Signal”

Repeater
reports “NO
GPS Signal”

Repeater
shows “No
GPS DEST”
or “No GPS
SOG” or “No
GPS CTE”

No power to
Repeater

Not getting NMEA
from the GPS
Receiver

Not getting NMEA
from the GPS
Receiver

No Waypoint
selected on GPS
Receiver

Check 12V supply,
fuse, and connections
between 10m cable
and GPS.
Check cable for
damage.

Check GPS Receiver is
set up to send NMEA
version 2.0 (or higher)
at 4800 Baud.

Check GPS Receiver
is on and has acquired
lock. Check wiring
connections.

Select waypoint

Repeater
shows “No
GPS POSN

Information
on Repeater
appears
different to
GPS Receiver

Receiver still
acquiring position

The Receiver
has not updated
its NMEA output

8

Wait for acquisition

Wait for update

TROUBLE SHOOTING

PROBLEM LIKELY CAUSE REMEDY

Information
on Repeater
appears
different to
GPS Receiver

Bearings are
different on
the Repeater

Left and
Right
symbols are
reversed.

The Receiver is
not set to display
knots, nautical
miles, etc.

The Receiver is
not set to
magnetic

Difference in
convention. Some
receivers show
direction TO
desired track,
others show your
position RELATIVE
to desired track.

Reset Receiver to
show Nautical units.

Set the Receiver to read
Magnetic bearings. If
true readings are
desired, set Receiver to
magnetic, and set zero
magnetic deviation

Remember the
convention in use

IMPORTANT READ THIS BEFORE

UNPACKING INSTRUMENT

Prior to unpacking this instrument read and fully understand the installation instructions.
Only proceed with the installation if you are competent to do so. Nasa Marine Ltd. will
not accept any responsibility for injury or damage caused by, during or as a result of
the installation of this product. Any piece of equipment can fail due to a number of
causes. Do not install this equipment if it is the only source of information and its failure
could result in injury or death. Instead return the instrument to your retailer for full credit.
Remember this equipment is an aid to navigation and not a substitute for proper
seamanship. This instrument is used at your own risk, use it prudently and check its
operation from time to time against other data. Inspect the installation from time to time
and seek advice if any part thereof is not fully seaworthy.

LIMITED WARRANTY

Nasa Marine Ltd. warrants this instrument to be substantially free of defects in both
materials and workmanship for a period of one year from the date of purchase.
Nasa Marine Ltd. will at its discretion repair or replace any components which fail in
normal use within the warranty period. Such repairs or replacements will be made at
no charge to the customer for parts and labour. The customer is however responsible
for transport costs. This warranty excludes failures resulting from abuse, misuse,
accident or unauthorised modifications or repairs. In no event shall Nasa Marine Ltd.
be liable for incidental, special, indirect or consequential damages, whether resulting
from the use, misuse, the inability to correctly use the instrument or from defects in
the instrument. If any of the above terms are unacceptable to you then return the
instrument unopened and unused to your retailer for full credit.

Name

Address

Dealer Name

Address

Date of Purchase

Proof of purchase may be required for warranty claims.

Boulton Road, Stevenage, Herts SG1 4QG England

Nasa Marine Ltd.

Declaration of Conformity

NASA Marine Ltd declare this product is in compliance with the essential requirements of
R&TTE directive 1995/5/EC.
The original Declaration of Conformity certificate can be requested at [e-mail]

THIS PRODUCT IS INTENDED FOR USE ONLY ON NON SOLAS VESSELS