AUTOHELM ST50 PLUS Instruction Manual

Autohelm
GPS & NAVDATA
Operation and
Installation

Autohelm and SeaTalk are registered Trade Marks of
Nautech Limited
Autohelms
policy of continuous improvement and updating
may change product specifications
without prior notice
Copyright Nautech 1993

Package Contents
The following items are included in the ST50 Plus GPS and Navdata
packages :
1 .

ST50 Plus control head
2 .

Fixing studs (2 off)
3 .

Thumb nuts (2 off)
4 .

Control head cover
5 .

Power cable
6 .

NMEA cable
7 .

Security sticker
8 .

Fitting template
9 .

Operation
and Installation handbook
10 . Worldwide Service Centre handbook
11 . Warranty document

Contents
Introduction . . . ... . . ... ... ... . .... . . ... . . .... . ... . . . . ... . . . . ... . . ... . . ... . . .... . ... 1
Chapter 1 : Control Head Installation .... ... . ... ... . .... . ... ... . . . . .... . . . . 3
1 .1 Siting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ................... . . . . . . . . . . . . . 3
1 .2 Mounting
Procedure
. .. . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1 .3 Power Supply (stand-alone operation) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6
1 .4 Power Supply (SeaTalk operation) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1 .5 Connection of Separated Instruments . . .............................. 7
1 .6 Ring Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ................. . . . . . . . . . . . . . 8
1 .7 Connection to SeaTalk Compatible Autopilots . . . . . . . . . . . . . . . . . . . . . . 8
1
.8 Connection to a Position Transducer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Chapter 2 : Fault
Finding
and Maintenance . . . . . .... . . . . ... .... . . . . ... . 11
2 .1 Fault Finding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
2 .2 Maintenance . . . . . . . . . . . . . . . ................. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Chapter 3 : Operation . . . .... . ... ... ... . .... . ... ... .... . ... . . .... . . ... . . ... . . . 13
3 .1 Display key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
3 .2 Waypoint Display
and
Entry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.16
3 .3 Sail Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
3 .4 Man Overboard . . . . . . . . . . . . . . . . . . . . . . . . . . . ............... . . . . . . . . . . . . . . . . . . 22
3 .5 Anchor Watch ........... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
3 .6 Dead Reckoning Mode . . . . . . . . . . . . . . . ................. . . . . . . . . . . . . . . . . . . 24
3 .7 Operation
with SeaTalk Autopilots ................. . . . . . . . . . . . . . . . . . . 25
3 .8 Operation with a Navcenter . . . . . . . ................... . . . . . . . . . . . . . . . . . .
26
3 .9 Position Correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
3 .10 Display Contrast . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Chapter 4 : CODE Lock Security . . . . . . .... . ... ... . . ... ... . . . . ... ... . .... . . 29
Chapter 5 :
Calibration
. . . . .... . . . . ...
... . .... . ... . . . . . . . .... . ... ... . . . . .... . . 33
5 .1 Initial Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34
5 .2 Intermediate Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
36
5 .3
Extended Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Chapter 6 : General Specification
. . . . . .... . ... ... . . . . . . ... . . . . ... . . . ... . . . 39

Introduction
The ST50 Plus GPS and Navdata instruments are repeaters
that receive
positional fixes via either NMEA or SeaTalk, from the GPS
satellite system
or the Loran/Decca beacon network .
The GPS system comprises of 24 satellites (operating globally 24 hours a
day) grouped into six separate orbits . Up to 5 of the 24 satellites are
tracked at any one time, and the difference between the unique signal
from
each satellite is used by the ST50 Plus GPS receiver to calculate
your exact position .
The ST50 Plus GPS and Navdata
units also incorporate a security feature
designed to protect instruments mounted in vulnerable areas, such as the
cockpit or helm .
Thank you for purchasing an Autohelm product . May we take this
opportunity to wish you years of trouble free operation .

Chapter 1 : Control Head Installation
1 .1 Siting
The ST50 Plus GPS/Navdata
is designed
for
above or below deck
installation where it is :
" Easily readable by the helmsman
" Protected against
physical damage
" At least 230mm (9in) from
a compass
"
At least 500mm (20in) from radio receiving equipment
" Accessible from behind for ease of installation and cable running
Caution :
To prevent
moisture forming on the display window, the ST50 Plus
GPS/Navdata 'breathes' through a small vent in the cable boss .
Therefore, the control head mustbe sited where the rear
case
is
protected from contact with water .
The rear case is fitted with afoam gasket to form a water-tight
seal
between the instrument and the selected installation face .

1
Cable boss 2 Fusing studs 3Thumb nuts
4 Gasket
1 .2
Mounting Procedure
1 .

Make sure that the selected
location is clean, smooth and flat .
2 .

Apply the self-adhesive template
(supplied) to the selected location
and mark the centres for the
fixing studs (2) and the cable boss (1) .
3 .

Drill
two 4mm (5/32in) clearance holes
for the fixing studs (2) through
the
bulkhead . Remove the template .
4 .

Cut the
clearance hole for the cable boss
(1) using a 50mm (2in)
diameter cutter .
5 .

Screw
the two fixing studs (2) into the
control head .
6 .

Pass the SeaTalk
cable and transducer tails through the
cable-boss
(1) clearance hole
.
7 .

Assemble the
control head to the bulkhead and secure from
behind
using the thumb nuts (3) .

Bracket Mounting
The ST50 Plus GPS/Navdata can,
as an alternative, be bracket mounted
using the Autohelm Mounting Kit (Catalogue No . D130)
.
Note : Because the instrument breathes through the vent in the rear case,
this bracket is for interior use only .
Flush
Mounting
A flush mounting kit is available for installations where a flush mount is
required or more desirable . Full installation instructions are provided with
the kit (Catalogue No . D187) .

1 . 3 Power Supply (stand-alone operation)
1 .

Connect the 2m (6ft .) power supply cable to the distribution panel
.
2 .

Cut the
cable to length and connect the red wire to the
+12V terminal
and
screen to the OV terminal .
3 .

Cut back
and insulate the yellow wire .
4 .

Protect
the circuit with a 5A circuit breaker .
Longer runs to the vessels
power supply can be made using one of the
SeaTalk Extension
Cables .
1 .4 Power Supply
(SeaTalk operation)
All instruments in a SeaTalk
system receive power and information from
the SeaTalk bus . Each
instrument has two SeaTalk connectors (3 pin) on
150mm (6in) tails . To supply power and information to the instrument
simply plug the tails from adjacent instruments into the ST50 GPS/
Navdata tails .