ComNav 11101 User manual

ComNav 1101 Autopilot
NOTE: In the case of differences of interpretation as regards the terms used in various translations of this manual,
the English version shall be regarded as correct and shall supersede all other versions.
Copyright © 2004 by ComNav Marine Ltd.
This manual may not be reproduced in whole or in part without written permission from ComNav Marine Ltd.
Printed in Canada
1101 Autopilot System
Installation and Operation Manual
Version 6.0
Serial #
ComNav Marine Ltd.
15 - 13511 Crestwood Place, Richmond, BC, Canada V6V 2G1
Phone: [phone] Fax: [phone]
Internet: www.comnavmarine.com e-mail: [email protected] Document PN
29010009
06/11/02

ComNav 1101 Autopilot
Welcome
Congratulations on your purchase of ComNav Marine’s 1101
Autopilot System! At ComNav, we are proud of our prominence as a
leader in the design and manufacture of marine autopilot systems.
Our dedication to performance and reliability will ensure your
satisfaction with the ComNav 1101. Developed as a result of
ComNav’s many years of experience in autopilot design, the 1101
system provides better performance and more features than any
other autopilot in its class.
Yours truly,
Don morris
Executive Vice President
ComNav Marine Ltd.

ComNav 1101 Autopilot
Warranty Notice
Prior to the installation and/or operation of the Equipment,
ensure that you read, understand and accept the condi-
tions of the warranties as detailed in Section 10 of this
manual.
Operator’s Warning
This Autopilot will automatically steer your vessel, however
it is only an aid to navigation. Its performance can be
affected by many factors including equipment failure,
environmental conditions and improper handling or use.
This system does not reduce your responsibility for the
control of the vessel when underway. You must always be
in a position to monitor the course, supervise the Autopi-
lot, and resume manual control if the need to do so arises.
Whenever underway, your vessel must be under the control
of a qualified and alert person.

ComNav 1101 Autopilot
Table of Contents
About This Manual - Section 1
-ImportantTermsinthisManual.....................................................................................................
How Autopilots Work - Section 2
-BasicAutopilotSystem.................................................................................................................
-BasicOperation............................................................................................................................
-Tide,WindandCurrent..................................................................................................................
-FollowingaTrackWithanAutopilot................................................................................................
-PowerSteer..................................................................................................................................
System Overview - Section 3
-ControlHead................................................................................................................................
-SignalProcessingUnit..................................................................................................................
-Compasses..................................................................................................................................
-FluxgateCompass.....................................................................................................................
-MagneticCompass....................................................................................................................
-MagneticCompassSensor........................................................................................................
-OtherCompasses......................................................................................................................
-RudderFollower............................................................................................................................
-DistributionBox............................................................................................................................
-OptionalEquipment.......................................................................................................................
-HeadingRateStabilizer..............................................................................................................
-RudderAngleIndicator(RAI)3”..................................................................................................
-SecondaryControlHeads..........................................................................................................
-AuxiliaryStation........................................................................................................................
-RemoteControls.....................................................................................................................
Installation - Section 4
-TechnicalRequirements................................................................................................................
-ControlHead................................................................................................................................
-SurfaceMounting......................................................................................................................
-AngleBracketMounting..............................................................................................................
-SignalProcessingUnit..................................................................................................................
-DistributionBox............................................................................................................................
-DistributionBoxConnections.........................................................................................................
-AutopilotPower.........................................................................................................................
-UnswitchedPower.....................................................................................................................
-Port/StbdOut...........................................................................................................................
-SwitchedPower.........................................................................................................................
-SpeedControl...........................................................................................................................
-+5VDC/Common......................................................................................................................
-MotorMonitor.........................................................................................................................
-JogSwitchInputs....................................................................................................................
-RudderFollower.......................................................................................................................
-NavSignal/Return...................................................................................................................
-RAISignal/Return....................................................................................................................
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ComNav 1101 Autopilot
Table of Contents (continued)
-CompassInstallation..................................................................................................................
-ComNavFluxgateCompass.....................................................................................................
-MagneticCompasses..............................................................................................................
- Mounting ComNav Compass Sensor .........................................................................................
-RudderFollower..........................................................................................................................
-OtherRudderFollowers............................................................................................................
-HeadingOutputInterface............................................................................................................
-NMEA0183Output.................................................................................................................
-AD-10SOutput........................................................................................................................
-Post-InstallationChecks..............................................................................................................
-HydraulicChecks.....................................................................................................................
-ElectricalChecklist..................................................................................................................
Getting Started - Section 5
-Introduction...................................................................................................................................
-STANDBYMode...........................................................................................................................
-On............................................................................................................................................
-Off............................................................................................................................................
-ChangingModes.......................................................................................................................
-Menu........................................................................................................................................
-Brightness................................................................................................................................
-Contrast...................................................................................................................................
-BatteryVoltage.........................................................................................................................
-POWERSTEERMode...................................................................................................................
-Menu........................................................................................................................................
-DocksideSetup............................................................................................................................
-Toperformanormal“Reset”.....................................................................................................
-Toperforma“FullReset”..........................................................................................................
-RudderDriveTest......................................................................................................................
-CompassConfiguration.............................................................................................................
-RudderHard-OvertoHard-overtime...........................................................................................
- Digital Rudder Angle Indicator (RAI) Adjustment .........................................................................
- Check External Rudder Angle Indicators (RAI) ............................................................................
-SeaTrials...................................................................................................................................
-FluxgateCompassCompensation.............................................................................................
-CompassReadout...................................................................................................................
-TestPOWERSTEERMode.......................................................................................................
Basic Operation - Section 6
-Introduction..................................................................................................................................
-AUTOPILOTMode........................................................................................................................
-DodgeFunction............................................................................................................................
-SpecialTurns...............................................................................................................................
-EmergencyTurn........................................................................................................................
-UTurn......................................................................................................................................
-ContinuousCircleTurn..............................................................................................................
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ComNav 1101 Autopilot
-SteeringResponse.......................................................................................................................
-Rudder.....................................................................................................................................
-CounterRudder.........................................................................................................................
-TurnRate..................................................................................
................................................
-Yaw.................................................
..........................................................................................
-Fast/SlowSpeed.......................................................................................................................
-TransfertoAux/RemoteControl.....................................................................................................
-SeaTrialsinAUTOPILOTMode......................................................................................................
- Effects of Speed on Turning Performance ...................................................................................
-SetSpeedTripPoint..................................................................................................................
-SteeringParametersMenu.......................................................................................................
-SlowSettings..........................................................................................................................
-FastSettings...........................................................................................................................
-Yaw.........................................................................................................................................
-TestDodgeFunction................................................................................................................
-SetupandTrialSpecialTurns...................................................................................................
-AdjustingforSpecialConditions...................................................................................................
-WaveAction............................................................................................................................
-VerySlowSpeed.....................................................................................................................
-FollowingSeas........................................................................................................................
-Current,WindandTide............................................................................................................
Advanced Operations - Section 7
-Introduction..................................................................................................................................
-NavigationInterface......................................................................................................................
-SteeringAlongaTrack..................................................................................................................
-SteeringaDirectBearing..............................................................................................................
-ProblemsinNAVMode.................................................................................................................
Setup & Sea Trials Checklist - Section 8......................................................................................
Problem Solving - Section 9
- Problems in DOCKSIDE SETUP Mode ............................................................................................
- Problems During Normal Operation of the Autopilot .........................................................................
-ErrorMessages............................................................................................................................
WarrantyInformation-Section10..............................................................................................
Specifications - Section 11
-General........................................................................................................................................
-CECompliance.............................................................................................................................
User’s Notes and Settings - Section 12 ......................................................................................
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Table of Contents (continued)

ComNav 1101 Autopilot
List of Figures and Tables
Figure1—BasicAutopilotSystem................................................................................................
Figure 2—Heading change in PILOT mode .....................................................................................
Figure3—1101AutopilotSystem.................................................................................................
Table 1—ComNav Remote Controls for use with 1101 Autopilot ...................................................
Figure4—FlushMountDiagram
....................................................................................................
Figure 7—1101 Distribution Box Connections ...............................................................................
Table 2—Minimum Recommended Wiring Gauges ..........................................................................
Figure 8—1101 Drive System Options & Interconnections .............................................................
Figure 5—Angle Bracket Mounting Diagram ...................................................................................
Figure6—SPUMountingDiagram.........................................
........................................................
Figure 9—Magnetic Compass Sensor Installation ........................................................................
Figure11—DODGEManeuver.............
..........................................................................................
Figure12—E
mergencyTurn..........................................................................................................
Figure13—U-Turn.................................................................
.......................................................
Figure14—ContinuousCircleTurn.............
...................................................................................
Table5—TurnRate
CorrelationTable.............................................................................................
Figure 10—Rudder Follower Linkage Detail ..................................................................................
Figure15—VesselResponses....................................................................................................
Table 3—Rudder Follower Cable Connections ..............................................................................
Table 4—Connections for Heading Output Cable ..........................................................................
Figure 16—Representation of Track and Bearing to Destination ......................................................
Figure 17—Response of Vessel to Cross-Track Error ......................................................................
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ComNav 1101 Autopilot1- 1 ABOUT THIS MANUAL
1. About This Manual
This manual provides essential information for the safe and reliable
operation of the 1101 Autopilot System. You are urged to read this
manual in its entirety before you use your Autopilot for the first time,
and to keep it handy until you become thoroughly familiar with the
operation of your Autopilot.
Throughout this manual, you will see a number of different typefaces
used, as well as some distinct phrases, or “jargon”. Please take a
moment to become familiar with the following terms:
Important Terms in this Manual
Modes of Operation
Specific “modes of operation” are placed in bold uppercase lettering.
Example: POWER STEER mode.
Button
1101 Control Head buttons and controls are placed in uppercase lettering.
Example: the COUNTER RUDDER button.
System Component
Specific system components are capitalized.
Example: the 1101 Control Head, or a Handheld Remote Control.
LCD Display
Text that appears in the LCD display is in quotation marks.
Example: “E-Turn”
“press”
A button “press” refers to a single momentary activation of a particular button.
“double-press”
Press and release the indicated button twice in rapid succession.
Although this sounds a little complicated, it is actually very easy to do. Many users familiar with
desktop computers perform a similar function when they “double-click” their mouse pointer.
“press and hold”
Press and hold the indicated button for a minimum of one-half of a second.
This time delay is purposely programmed for the operation of some buttons to prevent casual or
accidental activation of the button function. For example, pressing the SPEED button can, depend-
ing on system configuration, drastically alter the steering performance of the Autopilot.
“maintain”
Hold the indicated button for as long as required to achieve a given result.
For example, to dodge, press either the PORT DODGE or STARBOARD DODGE button, and maintain
it in that position until the vessel has dodged clear of any obstructions in its path.

ComNav 1101 Autopilot
2. How Autopilots Work
The purpose of this section is to briefly describe in general terms what
an Autopilot does and some of the things you should expect when
using an Autopilot with your boat. As well as this section, you must
carefully read all the operating instructions in other parts of this manual
before operating your autopilot.
Basic Autopilot System
Figure 1 is a block diagram of the major components of an Autopilot
system.
The Compass indicates the direction in which the boat is pointed,
called the actual heading. Depending on the type of boat, you may
be using a magnetic compass, an electronic fluxgate compass or a
gyroscopic compass. A reliable Compass is absolutely vital to the
autopilot because without a compass the pilot has no way of know-
ing which way the boat is headed.
Figure 1—Basic Autopilot System
HOW AUTOPILOTS WORK 2 - 1

ComNav 1101 Autopilot2- 2 HOW AUTOPILOTS WORK
The actual heading is fed electronically from the Compass to the Pro-
cessor, which is the heart of the Autopilot. The Processor contains
the microprocessors, electronic hardware and sophisticated control
software necessary to steer the boat.
The Control Head, normally located in the wheelhouse, is the inter-
face between the user (that’s you) and the Autopilot. The Control
Head displays information about what the Autopilot is doing. It has
various controls (buttons or knobs) which allow the user to give com-
mands to the Autopilot.
The final part of the picture is the steering system.
In order for the
Autopilot to steer the boat, there must be some sort of steering actua-
tor capable of moving the rudder independently of the ship’s wheel.
This might be a hydraulic steering ram which acts on the tiller or an
electric motor connected to the steering cables. Electronic signals
from the Processor signal the Steering Actuator to move the rudder.
Your Autopilot also will have a Rudder Feedback, a device which tells
the Processor what position the rudder is in at any given time.
Basic Operation
Say, for example, the Autopilot was steering your boat northwest and
you wished to change direction to northeast. To initiate the turn you
would turn the knob on the Control Head to set the desired heading to
450 (i.e. northeast). The Processor would compare this to the boat’s
actual heading of 3150 (northwest), as indicated by the Compass, and
calculate a difference of 900 . This in turn would cause the Processor
to send a signal to the steering system to move the Rudder to star-
board so that the boat turns to the right. The Processor verifies that
the Rudder has moved by reading its position from the Rudder Feed-
back.
As the boat turns, the difference between the desired heading and the
actual heading gets smaller and the Processor starts to ‘back off” the
rudder so that the boat does not overshoot the desired heading. Even-
tually, the actual heading will match the desired heading. The Proces-
sor will keep steering the boat on a heading of 450 , plus or minus 1/20 ,
until new instructions are received from the Control Head.
Figure 2 shows a vessel turning in AUTOPILOT mode.
Your ComNav Autopilot maintains a desired heading when it is in
AUTOPILOT mode. When the user first selects AUTOPILOT mode, the
Autopilot will use the current actual heading as the desired heading.
This important feature prevents the Autopilot from executing an unex-
pected turn when you first select AUTOPILOT mode.

ComNav 1101 Autopilot
Tide, Wind and Current
If your boat encounters a tide, crosswind or current, the boat will be
pushed away from the desired heading repeatedly, each time in the
same direction. After the Autopilot has made several corrections, the
Processor will simply maintain the rudder a few degrees to port or
starboard of the center position to counter the effect of wind, tide or
current. This feature, known as “trim”, will keep your vessel pointed
in the right direction.
Figure 2—Heading change in PILOT mode
HOW AUTOPILOTS WORK 2 - 3

ComNav 1101 Autopilot2- 4 HOW AUTOPILOTS WORK
Following a Track With an Autopilot
So far, we have seen how an Autopilot operates in AUTOPILOT mode.
In this mode, a new desired heading must be selected on the Control
Head each time you wish to change direction. This is handy for short
trips, when a boat is working or when you can see your objective. For
longer trips, which might involve a number of legs, it would be useful
to be able to pre-program your Autopilot to follow a given track. All
ComNav Autopilots will allow you to do just that.
Before using this feature, the Autopilot must be connected to an exter-
nal source of navigation data such as a LORAN C receiver, a chart
plotter or a GPS receiver. Fortunately, most of the hundreds of com-
mercially available navigation devices transmit data in the NMEA 0183
format, so interfacing a navigation device to the ComNav Autopilot is
relatively simple.
A long passage will consist of a series of waypoints which are discrete
locations on the water’s surface defined by their latitude and longi-
tude. These waypoints are entered into the navigation device. The
navigation device is able to determine the current location of the boat
and calculate a course to steer to reach the next waypoint.
Now the Autopilot is switched into NAV mode. The Processor reads
the information from the navigation device, which includes a course to
steer to the next waypoint and the crosstrack error, which is the dis-
tance (in nautical miles), from the boat to the desired track. Using
these two pieces of information, the Processor steers the shortest
possible course to the next waypoint. Tides, crosswinds or currents
are compensated for automatically each time the navigation device
updates the crosstrack error.
As the boat nears a waypoint, the Autopilot will alert the user by acti-
vating an alarm. When a waypoint is reached, the Processor will turn
the boat to head to the next waypoint. If the last waypoint is reached,
the boat will circle the waypoint until the Autopilot either is switched
out of NAV mode or given new instructions. Because the boat will turn
automatically and without input from the user, when planning the trip it
is crucial that the user verify that there will be sufficient room to ex-
ecute the turn at each waypoint.
Power Steer
Some Autopilots have a POWER STEER mode which allows Full Follow
Up steering. Control is usually through two buttons on the Autopilot.
One button will move the rudder to starboard, the other button will
move it to port. Using the buttons, the rudder can be placed in any
desired position where it will remain. This feature is useful when dock-
ing or maneuvering because the person steering the vessel can take
their hands off the controls between rudder movements.

ComNav 1101 Autopilot
3. System Overview
At the core of the Autopilot System is a microprocessor-based PID
(Proportional-Integral-Differential) controller. This controller works
from either a high quality, externally gimbaled magnetic ship’s
steering compass fitted with a Magnetic Compass Sensor, or a
direct earth’s field sensing Fluxgate Compass.
Heading information is compared against the commanded heading;
from this information, the desired rudder position is calculated. The
desired rudder position is then compared against the actual rudder
position transmitted by the Rudder Follower. If they are not the
same, either the port or starboard output line is activated.
Both the port and starboard output lines are active low (i.e. they
switch to ground). Each is capable of driving up to a 3-amp load.
These output lines are designed to drive solenoid valves in a
hydraulic steering system.
A speed control signal is also available for use with variable speed
rudder drives. All of the outputs, either by themselves or with an
optional solid state relay box, can be adapted to operate a wide
variety of power steering systems. If the Autopilot is installed as a
retrofit, it is usually possible to use the existing steering installa-
tion.
The system is designed to operate on a wide variety of vessels
operating with power systems of either 12 or 24 VDC.
The 1101 Autopilot is equipped to interface with a GPS, Loran C, or
any other navigation device that outputs one of the NMEA 0183
formats at 4800 Baud.
The 1101 Control Head functions as the main interface between the
Autopilot System and the user. It contains a number of buttons and
an ADJUSTMENT knob through which the operator controls the
functions of the Autopilot. A large Liquid Crystal Display (LCD)
screen provides visual feedback of the operator’s commands and
shows the status of the Autopilot System at any given time while the
unit is powered up.
SYSTEM OVERVIEW 3 - 1

ComNav 1101 Autopilot3- 2 SYSTEM OVERVIEW
SPU
SIGNAL PROCESSING
UNIT
REMOTE EXPANDER
BOX (OPTIONAL)
101, 201, 211
REMOTE CONTROL
(OPTIONAL)
MOTOR DRIVE
INTERFACE
BATTERY
POWER SOURCE
SOLENOID OR
2ND STATION
(OPTIONAL)
CONTROL
HEAD
SHIP’S COMPASS
AUTOPILOT NMEA
HEADING OUTPUT
COMPASS SENSOR
OR FLUXGATE COMPASS
HYDRAULIC
PUMP
ROTARY FEEDBACK
RUDDER FOLLOWER
NMEA INPUT
FROM NAV DEVICE
JOG LEVER
(OPTIONAL)
RUDDER ANGLE
INDICATORS (RAI)
(OPTIONAL)
HEADING RATE
STABILIZER
(OPTIONAL)
LINEAR FEEDBACK
RUDDER FOLLOWER
OR
DISTRIBUTION BOX
The following section gives a brief description of the major compo-
nents that comprise the 1101 Autopilot System, their function, and
relationship to each other.
Figure 3—1101 Autopilot System
(showing possible interconnections between the Autopilot System, accessories and external equipment)

ComNav 1101 Autopilot
Control Head
The 1101 Control Head provides a means for the user to control the
Autopilot and monitor the system while it is in use.
The 1101 Control Head may be secured using the stainless steel
Angle Mounting Bracket included with the Autopilot System, or
surface mounted onto a console panel.
The Control Head connects directly to the Signal Processing Unit, or
‘SPU” as it is sometimes known, via a twelve conductor cable on
the rear of the unit. This cable comes complete with a special
connector on the end to allow it to quickly and easily plug into the
Control Head receptacle on the SPU. The Control Head should be
plugged in to the Auxiliary Station receptacle only if there is already
a separate 1101 Control Head connected to the Control Head
receptacle.
1101 Control Head
Part # 20050002
SYSTEM OVERVIEW 3 - 3
1) LCD DISPLAY SCREEN
2) STBY/OFF button
3) POWER STEER button
4) AUTOPILOT button
5) NAV button
6) DODGE PORT button
7) SPEED button
8) ADJUSTMENT KNOB
9) TURN button
10) DODGE STARBOARD button
11) RUDDER button
12) CNTR RUDDER button
13) TURN RATE button
14) YAW button
14
97
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ComNav 1101 Autopilot3- 4 SYSTEM OVERVIEW
1) LCD DISPLAY SCREEN
When the Autopilot power is on the screen displays either the actual
heading of the vessel or the commanded heading (depending on
which mode it is in). It also displays additional information such as
mode of operation and various menus.
2) STBY/OFF button
When power is initially turned on, “STANDBY” appears at the bottom
of the display screen. While in this mode, the Autopilot will not
exert any control over your vessel. STANDBY mode is used when
you want manual control of the vessel, or when you want to change
the Autopilot parameters via the
Standby menu.
When pressed and held for approximately 2 seconds, this button
turns off the Autopilot.
3) POWER STEER button
When pressed, this button places the Autopilot into POWER STEER
mode. This mode allows you to steer the vessel through the
Autopilot by using the DODGE PORT and DODGE STARBOARD
buttons.
4) AUTOPILOT button
Pressing this button places your vessel in the hands of the 1101
Autopilot. You can control the vessel’s heading by using the
ADJUSTMENT KNOB. Obstacles can be avoided by using the
DODGE PORT or DODGE STARBOARD buttons.
5) NAV button
If your vessel is equipped with a GPS, Loran C, or another
Navigation Device, this button enables the Autopilot to steer from
NMEA 0183 data provided by those devices.
6) DODGE PORT button
In POWER STEER mode
pressing and holding this button moves the
rudder to port. Pressing this button while in AUTOPILOT or NAV
modes allows you to avoid obstacles in the vessel’s path by turning
to port, and then automatically recover your original heading or track
afterwards.
7) SPEED button
This button allows you to manually switch between FAST and SLOW
steering parameters.
8) ADJUSTMENT KNOB
Used to adjust course in AUTOPILOT mode. Also used to change
various parameters stored within the 1101 Autopilot.
9) TURN button
Pressing this button while in AUTOPILOT mode initiates one of three
turn sequences—a U-turn, Emergency Turn, or a Continuous Circle
Turn.
The turn is not executed until either the DODGE PORT or the
DODGE STARBOARD button is pressed to indicate in which direction
the turn is to be made. The type of turn to be executed is selected
during setup.

ComNav 1101 Autopilot SYSTEM OVERVIEW 3 - 5
Signal Processing Unit
The SPU, as its name suggests, accepts a number of signals from
the other components of the Autopilot System and processes them
as necessary to control the movement of the vessel’s rudder so as
to maintain a given heading. As well as steering the vessel, the
sophisticated software within the SPU continually checks all aspects
of the Autopilot’s performance, and will advise the user via the
Control Head if any problems are detected.
1101 Signal Processing Unit
Part # 20050003
10) DODGE STARBOARD button
In POWER STEER mode pressing and holding this button moves the
rudder to starboard. Pressing this button while in AUTOPILOT or NAV
modes allows you to avoid obstacles in the vessel’s path by turning
to starboard, and then automatically recover your original heading or
track afterwards.
11) RUDDER button
In AUTOPILOT or NAV modes, immediately brings up the Steering
Parameters menu and positions the cursor at the “Rudder” value.
Use the ADJUSTMENT KNOB to change this value if desired.
12) CNTR RUDDER button
In AUTOPILOT or NAV modes, immediately brings up the
Steering
Parameters menu and positions the cursor at the “Cntr Rudder”
(Counter Rudder) value. Use the ADJUSTMENT KNOB to change this
value if desired.
13) TURN RATE button
In AUTOPILOT or NAV modes, immediately brings up the Steering
Parameters menu and positions the cursor at the “Turn Rate” value.
Use the ADJUSTMENT KNOB to change this value if desired.
14) YAW button
In AUTOPILOT or NAV modes, immediately brings up the Steering
Parameters menu and positions the cursor at the “Yaw” value. Use
the ADJUSTMENT KNOB to change this value if desired.

ComNav 1101 Autopilot3- 6 SYSTEM OVERVIEW
Compasses
The 1101 Autopilot will function with heading input from either a
ComNav Fluxgate Compass or Magnetic Compass with a 12 KHZ
Compass Sensor.
Fluxgate Compass
Specifically designed for ComNav autopilots, the ComNav Fluxgate
Compass directly senses the earth’s magnetic field. The unit
incorporates a heeling coil for better performance when the vessel
is either rolling or heeled. The Fluxgate Compass is a sealed,
waterproof unit, 142 mm (5.6") square which may be mounted on a
deck, shelf or bulkhead. A single connection with a 3 m (10') cable
plugs into the 1101 SPU.
Magnetic Compass
ComNav can supply high quality, externally gimbaled Magnetic
Compasses of either 5" or 6" diameter. These compasses may be
purchased as either bracket mount or binnacle mount. Compensat-
ing spheres and arms are available for binnacle compasses.
Consult your ComNav dealer or the factory for part numbers
Magnetic Compass Sensor
The 12 KHZ Magnetic Compass Sensor senses the position of the
compass card of an externally gimbaled magnetic compass. The
sealed unit attaches to the bottom of a ComNav supplied magnetic
compass. A single connection with a 3 m (10') cable plugs into the
1101 SPU.
Other Compasses
ComNav recommends the use of ComNav supplied compasses for
best 1101 performance but you may choose to use either a fluxgate
compass or a magnetic compass from another manufacturer. See
your dealer or contact the factory for information on interfacing
these compasses with the 1101 Autopilot.
Fluxgate Compass
Part # 20320004
Binnacle Mount Compass
(6” binnacle compass shown)
Bottom Mount
12KHZ Compass Sensor
Part # 30320002

ComNav 1101 Autopilot SYSTEM OVERVIEW 3 - 7
Distribution Box
Part # 20010001
Medium Duty Rudder Follower
Part # 20330008
Rudder Follower
The 1101 Autopilot is supplied with a ComNav Medium Duty Rudder
Follower.
The Rudder Follower is used to transmit the position of the vessel’s
rudder to the SPU. It should be connected to whichever part of the
steering system the Autopilot controls. Normally, this is the vessel’s
rudder, however, if the vessel has 2-stage steering where the
Autopilot drives a control or servo ram, the Rudder Follower should
be mounted to the servo ram rather than the rudder.
Some 1101 Installations may use a ComNav Linear Feedback (Part
# 81957) or a Heavy Duty Rudder Follower (Part # 83634). These
units come with installation instructions.
Distribution Box
The Distribution Box provides a neat and tidy way to wire the SPU to
the power supply, output solenoids, navigation computer, Rudder
Angle Indicators (RAls) and other accessories.

ComNav 1101 Autopilot3- 8 SYSTEM OVERVIEW
This subsection describes optional equipment that may be
configured into the Autopilot System. These are Auxiliary Station
Control Heads, Remote Controls, Jog Switches, Remote Control
Expanders, Heading Rate Stabilizers and Rudder Angle Indicators (RAI).
Optional Equipment
Heading Rate Stabilizer
Perhaps the single greatest factor affecting Autopilot performance is
the quality of the compass heading information it receives.
Compass error due to pitch and roll, high turn rates and high
speed turns are common to both fluxgate and magnetic compasses.
Northerly turning error is another phenomenon that affects both
types of compasses, particularily at higher latitudes, due to an
increase in the earth’s vertical magnetic field component.
The sideways acceleration of a vessel in a high speed turn will also
affect the accuracy of compasses.
ComNav’s Heading Rate Stabilizer minimizes the effect of these
factors.
The Heading Rate Stabilizer measures the horizontal
component of the rate of change in the vessel’s heading and
adjusts the compass reading to minimize the effects of pitch and
roll, fast turn rates and northerly turning error.
The heading output provided to the Autopilot is dramatically
improved in terms of dynamic responsiveness and stability,
enabling the Autopilot to perform more accurately and efficiently.
The ComNav Heading Rate Stabilizer is designed to work with
ComNav’s Fluxgate Compass (Part # 92142).
Heading Rate Stabilizer
Part # 20320005