COURSEMASTER CM82i User guide

COURSEMASTER
AUTOPILOTS
A
ustralia's world leader in autopilot technolo
gy
CM82iSYSTEM MANUAL
11-09

CM82iSYSTEM MANUAL
Your Coursemaster CM82iautopilot system is engineered for accurate and
reliable steering. But remember that it cannot keep a lookout.
SAFE NAVIGATION IS ALWAYS YOUR
RESPONSIBILITY.
COURSEMASTER AUTOPILOTS PTY LTD.
2/66 LOWER GIBBES STREET,
CHATSWOOD NSW. AUSTRALIA 2067
ABN 25 001 306 369
Phone [phone]
Fax [phone]
E-mail [email protected]
Website www.coursemaster.com
Copyright 2009. This manual, the mechanical and electronic design of the CM82i
autopilot system and its associated software are protected by copyright. Unauthorised
copying may result in prosecution.
11-09

QUICK START
•Press the STANDBY key to turn the system on.
•Hold down the STANDBY and PILOT keys together to turn the system off.
•Steer to the desired course and press PILOT.
•Use the arrow keys to change course.
•To engage the auto-navigate system, hold the PILOT key down for two
beeps. Press PILOT once to cancel the auto-navigate mode.
•To select the menu, hold the STANDBY key down for two beeps. Scroll
down with single presses of the STANDBY key. Hold the STANDBY key
down for two beeps to exit the menu.

CM82iSYSTEM MANUAL
CONTENTS
QUICK REFERENCE
1. SYSTEM DESCRIPTION
1.1 Introduction to autopilots 1-1
1.1.1 Conventional autopilots 1-1
1.1.2 Steering Control 1-3
1.1.3 The ‘intelligent’ autopilot 1-4
1.1.4 Course holding and turning 1-4
1.1.5 Options 1-5
1.1.6 Working with other Equipment 1-5
1.2 The CM82iSystem 1-6
2. OPERATING INSTRUCTIONS
2.1 The Control Head 2-1
2.2 Getting Started 2-2
2.3 Normal Operation 2-3
Switching on
Switching off
Autopilot
Adjusting the course
Auto-navigate
2.4 The Menu 2-6
2.5 Alarms 2-11
2.6 Recommended settings 2-12
3. INSTALLATION
Step-by-step Summary 3-1
3.1 Junction Box 3-2
3.2 Control Head 3-4
3.3 Rate Gyro Compass 3-5
3.4 NMEA Interfaces 3-7
3.5 Steering Drive 3-8

CONTENTS
4. TROUBLE-SHOOTING
4.1 General 4-1
4.2 Error messages 4-2
4.3 Other faults 4-3
4.4 Fuses 4-4
5. SYSTEM SPECIFICATIONS 5-1
6. MAINTENANCE AND WARRANTY 6-1
QUICK REFERENCE
INSTALLATION
•Mount the Junction Box as described in Sect 3.1
•Mount the Control Head as described in Sect 3.2
•Mount the Compass as described in Sect 3.3
•Install the Steering Drive as described in Sect 3.5.
•Connect optional attachments as described in Sect 3.4
•Carry out the system set-up as described in Sect 2.2

THE MENU
BACKLIGHT
NORMAL/ROUGH
RUDDER FACTOR
RATE FACTOR
RATE GYRO ON/OFF
HEADING CONTROL HEADING ADJUST
AUTO COMP CALIB
MANUAL COMP CALIB
MAG VARIATION
HEAD COMP/HDG/HDT
RUDDER CONTROL HELM LIMITS
TURN RATE LIMITS
AUTO BALANCE ON/OFF
STEER DRIVE
HELM ALERT
OTHER OPTIONS NMEA OUT HDG/HDT
PILOT DISPLAY A/B
COMPASS VOLTAGES
BALMONITORON/OFF
COLD START

1 SYSTEM DESCRIPTION
1.1 INTRODUCTION TO AUTOPILOTS
The main function of a marine autopilot is to hold the heading of a vessel on a
reference course which is held in the memory of the autopilot. When it is operating,
the autopilot continuously compares the vessel’s heading with a reference course, and
if they are different, it applies helm to bring the vessel back on course. Since there has
to be a compromise between the accuracy of course holding and the activity of the
rudder, the autopilot has controls which are set to strike a balance between these two
factors.
1.1.1 CONVENTIONAL AUTOPILOTS
A conventional autopilot is illustrated schematically in Fig 1.1
RUDDER
STEERING DRIVE
RUDDER STEM
CONTROL
POWER
TRANSDUCER
COMPASS
Figure 1.1 Basic components of a conventional marine autopilot.

System Description 1-2
The four basic components are a compass, an electronic control box, a rudder angle
sensor (transducer) and the steering drive.
A Junction Box, mounted below decks, contains most of the system electronics and a
Control Head, mounted at the steering station provides the interface with the user.
Modern autopilots perform other functions as well and this introduction explains how
these fit in with the basic function and how they provide a wider range of options for
the user.
When the autopilot is first turned on, it rests in an idle (STANDBY) state in which it
displays the heading, but does not steer the vessel. It is activated by switching it into
the PILOT state. At the moment this is done, the current heading is put into memory
as the reference course and the autopilot starts steering to hold the heading on this
reference course. The user can change the reference course at any time and the
heading will swing round to match the new course.
There is another way of setting the reference course. If the autopilot is connected to a
GPS navigation receiver, the heading is then controlled to place the vessel on a direct
track between the origin waypoint and the next waypoint.
1.1.2 STEERING CONTROL
When the vessel swings off course or the reference course is changed, the autopilot
should apply helm in a way, which brings the vessel onto course quickly, but without
overshooting the reference course. The correct rudder angle depends on the amount
of the error, the speed of the vessel, its size, the effectiveness of its rudder and the
weather conditions. This choice is managed by four parameters within the autopilot,
as follows.
Rudder Factor
The sensitivity or Rudder Factor sets how many degrees of helm are applied for a
given course error. A mid-range Rudder Factor setting applies half a degree of helm
for each degree off course. In large or slow vessels it would be more and in light, fast
boats it may be less.
Setting the rudder factor too high causes oversteering or ‘snaking’ as illustrated in Fig
1.2. Too low a setting causes understeer and a sluggish response. Fortunately, most
vessels tolerate a range of settings and still steer well.

System Description 1-3
UNDERSTEER
REFERENCE
COURSE
OVERSTEER
Figure 1.2. Illustration of oversteer if the rudder factor is set too high and understeer if
it is set too low.
Counter Rudder
Counter Rudder, or rate feedback, compensates for turning inertia and is generally
used in vessels above 8 m length. Near the end of a turn, counter rudder is applied to
slow the turn rate so that the heading settles accurately on the new reference course.
Counter rudder also improves stability in a following sea.
The action of the rate or counter-rudder during a turn is illustrated in Fig 1.3.
Generally, when the rate component is increased, vessels hold a course better but
react to changes in the reference course more slowly. Counter-rudder also improves
control for most vessels operating in a following sea.
REFERENCE
COURSE
NORMAL RUDDER
NEUTRAL RUDDER
COUNTER RUDDER
Figure 1.3 Rudder action during a turn in the RATE mode.

System Description 1-4
Sea State
When the Sea State or Control Mode is set to ROUGH, it introduces a ‘deadband’ in
the course control, so that rudder activity is reduced when the vessel rolls and yaws in
a heavy sea. Full rudder control is applied when the vessel yaws off course by more
than a preset amount.
Trim
Vessels often show a steering bias or offset, which can be due to weather, propeller
torque or towing a load off-centre. The autopilot responds to this by progressively
trimming the centre position of the rudder until the average heading of the vessel
equals the reference course.
1.1.3 THE ‘INTELLIGENT’ AUTOPILOT
An ‘intelligent’ autopilot, such as the CM82i,works on the same principles as those just
described, but with two practical differences. There is no rudder angle sensor. Instead,
the angle is calculated within the system, using inputs from the steering drive and the
compass. Secondly, some internal settings in the autopilot adapt themselves
automatically to conditions such as propeller torque and offset effects arising from the
weather and the trim of the vessel.
1.1.4 COURSE HOLDING AND TURNING
The CM82i is mainly intended for vessels in the 5 - 10 m range, usually with outboard
motors. These vessels have two features that affect course holding and turning. First,
they are more responsive to wind load and wave effects than heavy vessels and can
yaw quickly when hit by a wind gust, for example. Secondly, they are often used at
speeds above 15 kt and are therefore susceptible to the southerly/northerly heading
error effect.
The autopilot responds quickly to correct heading shifts caused by wind or waves and
a yaw of 3 degrees around the reference course is typical in choppy and windy
conditions. But when there is a constant weather offset, the automatic trim acts
progressively to apply weather helm and bring the average heading of the vessel onto
the reference course. This action may take 10 - 15 seconds to complete. The weather
helm effect can be seen particularly during a large course change. If the conditions
are not calm, the wind and wave load on the vessel will be different at the end of the
turn and the vessel may undershoot or overshoot the new reference course until the
trim adjusts to the new conditions.

System Description 1-5
The northerly/southerly heading error is a result of the dip angle of the earth’s
magnetic field lines. For vessels travelling above about 15 kt, it produces northerly
course holding errors in regions north of latitude 30N and southerly errors when south
of latitude 30S. The use of the CM437 Rate Gyro Compass overcomes this problem,
as well as reducing rudder activity in choppy conditions.
1.1.5 OPTIONS
As an alternative to using the standard rate gyro compass, the CM82i has an option to
use a digital heading input, which would typically come from a GPS compass. Note
that the course-over-ground data available from GPS navigation systems does not
respond quickly enough to be used as the primary heading input.
1.1.6 WORKING WITH OTHER EQUIPMENT
The physical and electrical environment in a boat can be harsh. This autopilot has
been engineered with this in mind and tolerates poorly regulated power supplies,
overloaded steering, radio transmitters, radars and the like. Conversely, it has also
been engineered to operate without causing interference to radio receivers and other
communications equipment. Coursemaster autopilots carry a CE mark to indicate
compliance with the relevant EMC standards. The installation sections of this manual
have been carefully developed to minimise problems when the autopilot is in this
environment. Please study and follow them!

System Description 1-6
1.2 THE CM82iSYSTEM
The core of the CM82i system consists of Control Head, Junction Box, Rate Gyro
Compass and Steering Drive. The system, together with its optional attachments is
illustrated in Fig 1.2 below.
JUNCTION BOX
CM840
CONTROL
HEAD
RATE GYRO
COMPASS
CM437
12V
POWER
DRIVE
STEER
RADAR /
PLOTTER
DIGITAL
HEADING
GPS
NAVIGATION
Figure 1.2 The CM82isystem.
CM840 Junction Box
The Junction Box contains the control microcomputer, the interfaces with other system
components and the steering drive electronics. All system cables are terminated in the
Junction Box. The drive system is robust and is designed to drive mechanical and
hydraulic pump steering systems.
CM82i Control Head
The Controller has four push-buttons to control the system and displays information on
the current operation of the autopilot.

System Description 1-7
CM437 Rate Gyro Compass
The CM437 Rate Gyro Compass combines a fluxgate sensor with a rate gyro.
Steering Drive
The autopilot is intended for hydraulic steering systems, of which there are a number
of options. A suitable drive may either by supplied by Coursemaster or the autopilot
may be connected to an existing steering drive on the vessel. One of the
recommended pumps, supplied by Coursemaster, is a 0.6 litre/min reversing gear
pump.

2 OPERATING INSTRUCTIONS
2.1 THE CONTROL HEAD
The display screen of the Controller (Fig 2.1) shows digital and text information
about the current operation of the autopilot. There are four keys which control the
operation and the functions of these keys are described below.
COURSEMASTER
STANDBY PILOT COURSE
CM82i
PS
STBY
Heading or
Reference Course
System Mode
Control keys
Message Line
Figure 2.1 The CM82iController panel.

Operating Instructions 2-2
______________________________________________________________
2.2 GETTING STARTED
Before operating the autopilot for the first time, it must be installed and adjusted as
described in Chapter 3. (If optional attachments are being used, these can be fitted
after initial trials of the system.)
To switch on for the first time, press the STANDBY key. The system enters a set-up
mode so that the size of the vessel can be entered and the steering gear calibrated.
The screen shows the prompt:
There are two choices. If you wish to examine some of the features without carrying
out the setup, select NO by pressing the left arrow. This will bypass the setup and
let you scroll through the displays, but there will be no response to the PILOT key.
The system will return to SYSTEM SETUP the next time it is turned on.
To carry out the setup, select YES by pressing the right arrow.
SETTING THE HULL LENGTH
The screen now shows:
STBY
Set the approximate boat length by using the arrow keys. These will step up or down
in 2 m steps. This is an important operation and sets the initial tuning of the autopilot
to values which best suit your vessel.

Operating Instructions 2-3
______________________________________________________________
Then press STANDBY again to calibrate the steering drive.
Centre the helm. Then watch the steering gear as you press the right arrow. It
should move a few degrees to starboard for each press of the key. If it moves the
wrong way, switch off the system and reverse the motor lead connections. Continue
pressing until 20 deg helm is applied. If you move too far, use the left arrow to bring
it back. It takes typically 8 – 10 key presses to apply 20 deg of helm. Then press
STANDBY. The helm will now pulse back to the centre and the display reads AUTO
RETURN as it moves back. The setup is now complete and the screen should show
its normal display.
If the helm does not return close to centre during this last operation, there may be air
in the hydraulic system and it should be bled again. Small centring errors will not
affect the operation of the autopilot.
THE SETUP IS NOW COMPLETE
2.3 NORMAL OPERATION
SWITCHING ON
Press the STANDBY key. The system does a self-test for a few
seconds and displays the version of software fitted to your
autopilot.
When the self-test is complete the normal STANDBY display
appears and shows the current heading of the vessel.
NAV REMOTESTBY PILOT STBY
Switching
On
S

Operating Instructions 2-4
______________________________________________________________
If a fault is detected during the self test, the Controller starts
beeping and the type of the fault is displayed after the self-test
period.
SWITCHING OFF
Press the STANDBY and PILOT keys together.
With the system in STANDBY, steer the vessel to the desired
heading and press PILOT. The autopilot will now lock onto that
heading and maintain it.
Autopilot Display Screens
There are two display options in PILOT mode. The left-hand
display is Mode A. It shows the Reference Course in large digits,
the selected steering mode and the rudder factor. Mode B shows
the current heading in large digits and the Reference Course
below it. The preferred mode may be selected via the PILOT
DISPLAY option in the menu.
PILOT PILOT
Mode A Mode B
Switching
Off
S P
Autopilot
P

Operating Instructions 2-5
______________________________________________________________
To adjust the current reference course, press either the left or
right arrow key. A single press changes the course by 1 degree.
Holding a key down changes the course continuously in 10
degree steps.
Note. In the auto navigate mode the reference will not change,
since it is controlled by the GPS system.
If a GPS receiver or other source of navigation data is connected,
the vessel can be steered to head towards a waypoint with
minimum cross-track error. Hold the PILOT key down for two
beeps to turn on auto navigation. The NAV symbol will appear at
the top of the screen. If no valid navigation sentence is being
received, the NAV symbol will blink on and off. Press the PILOT
key again to cancel the NAV mode.
2.4 THE MENU
The menu provides access to autopilot settings. Changing these is not essential for
correct operation, but may improve performance or bring other options into operation.
A navigation map for the menu is shown below. The menu can only be accessed in
the STANDBY mode.
Hold STANDBY down for two beeps. The first menu option should now show. Scroll
down the menu using single presses of the STANDBY key. Use the or right arrow
key to select a sub-menu, eg for heading control options. Use the left or right arrow
keys to change settings. Return to the main screen by holding STANDBY for two
beeps.
Adjusting
the course
Auto-
navigate

Operating Instructions 2-6
______________________________________________________________
THE MENU
BACKLIGHT
NORMAL/ROUGH
RUDDER FACTOR
RATE FACTOR
RATE GYRO ON/OFF
HEADING CONTROL HEADING ADJUST
AUTO COMP CALIB
MANUAL COMP CALIB
MAG VARIATION
HEAD COMP/HDG/HDT
RUDDER CONTROL HELM LIMITS
TURN RATE LIMITS
AUTO BALANCE ON/OFF
STEER DRIVE
HELM ALERT
OTHER OPTIONS NMEA OUT HDG/HDT
PILOT DISPLAY A/B
COMPASS VOLTAGES
BALMONITORON/OFF
COLD START
The use of each menu item is described below.

Operating Instructions 2-7
______________________________________________________________
BACKLIGHT The backlight for the display can be set to 4 different
brightness levels. Use the arrow keys to adjust.
CONTROL MODE The system is preset to the NORMAL mode, but may be
changed to operate in ROUGH Use the arrow keys to
select between the following:
NORMAL
Direct proportional control with a counter-rudder component
that be adjusted from the menu (see below).
ROUGH
This suits most vessels in heavy conditions. The control
has a deadband which permits a 5 deg yaw about the
reference course before correction is applied. Outside this
window, the control is as for the Normal mode. Rudder
activity and power consumption are therefore kept to a
minimum.
RUDDER FACTOR The Rudder Factor (or sensitivity) controls the amount of
helm applied for a given course error. This may be
increased or reduced using the arrow keys. There is more
about the rudder factor in Sec 2.6.
RATE FACTOR The RATE FACTOR controls the amount of counter rudder
applied in both control modes. Guidelines for setting it are
given in Sect 2.6.