ComNav P4 Remotes Series User manual

ComNav P4 Autopilot
Advanced Autopilot Systems
Installation and Operation Manual
PN 29010100

ComNav P4 Installation and Operation Table of Contents, List of Figures and Tables
Document PN 29010100 V1r0 - 2 -
Welcome
Congratulations on your purchase of a ComNav Marine P4 Advanced Autopilot System.
Developed using ComNav’s many years of experience in autopilot design, the P4 Autopilot
provides superior performance and advanced features, meeting or exceeding any other products
in their class.
At ComNav, we are proud of our cutting-edge design and market-leading manufacture of marine
autopilot systems. Our dedication to performance and reliability will ensure your satisfaction with
your ComNav product for years to come.
ComNav Marine Ltd.
#15 – 13511 Crestwood Place Richmond, B.C. V6V 2G1 Canada
Tel: [phone] • Fax: [phone]
Web: www.ComNav.com
E-mail:[email protected] -[email protected]
Warranty
Prior to the installation and/or operation of any ComNav equipment, please take a moment to
read and accept all warranty conditions as detailed in the Warranty Information section of this
manual.
WARNING
This Autopilot is for navigation assistance only. Whenever underway, your
vessel must always be under the control of a qualified and alert person who
regularly and consistently ensures that the course and position of the
vessel is correct and that the operating area is safe. You must always be in
a position to resume manual control if the need to do so arises.
This equipment is not intended or designed to replace any person or
persons on watch. A qualified individual should always be in a position to
monitor the vessel’s heading, and to monitor navigational hazards. The
operator should always be prepared to revert to manual steering
immediately if:
an undesired change of heading occurs
the heading is not maintained within reasonable limits
you are navigating in a hazardous situation
The performance of the Autopilot can be affected by many factors, including
equipment failure, environmental conditions, and improper handling or use.
Never place magnets or magnetic material near compasses connected to
the autopilot system.
The Autopilot should never be used in areas where it is considered unsafe
due to obstacles, other marine traffic, poor weather, or any other condition
that could create a dangerous situation, or where it may be unlawful.

ComNav P4 Installation and Operation Table of Contents, List of Figures and Tables
Document PN 29010100 V1r0 - 3 -
General Notice
This document, ComNav part number 29010100 Version 1 Revision 1, is the approved
Installation and Operation Manual for use with the ComNav P4 Advanced Autopilot System.
Where versions of this manual exist in other languages, the English language version shall be
considered authoritative.
About this Manual
This manual provides essential information for the safe and reliable operation of the ComNav P4
Advanced 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.
Typefaces, Common Phrases and Terms
Throughout this manual, you will see a number of different typefaces used, and several
commonly-used words and phrases with very specific meanings, to describe concepts and
actions that are fundamental to the operation of the autopilot. Please take a moment to become
familiar with the following:
• System Component
Specific system components are capitalized. Example: the Control Head
• Modes of Operation
Specific “modes of operation” are placed in bold uppercase lettering. Example: POWER
STEER mode.
• LCD Display
Text that appears in the LCD display is in quotation marks. Example: “Waypoint Arrival”
• Button
Control Head buttons and the knob are in bold small-caps lettering. Example: the TURN
button
• Press or momentary press
Press and release the indicated 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. If you use a personal
computer, you will find that this is similar to a “double-click” when using a mouse.
• Press and hold
Press and hold the indicated button for approximately 1 second.
• Press and maintain
Press and hold the indicated button for as long as required to achieve a desired result.

ComNav P4 Installation and Operation Table of Contents, List of Figures and Tables
Document PN 29010100 V1r0 - 4 -
Manual Format
This manual has been formatted to be printed on both sides of the pages, and on standard
North American Letter-size paper (8.5” x 11”).
If you have obtained this manual as a soft-copy, please note that it is in Adobe® Portable
Document Format (“pdf”), and so may be viewed and printed with Adobe Reader®, or
compatible pdf-format viewers.
When printing this manual with Adobe Reader®, you should select “duplex printing” (or the
equivalent term used by your printer’s software), in order to print it double-sided on the paper.
If your printer does not have built-in duplexing capability, you can still print this manual
double-sided by following the instructions that came with your printer for doing “hand
duplexing”.
You should also select the Auto-Rotate and Centre option in the Print Dialog box, de-select
the Choose Paper Source by PDF page size option, and set Page Scaling to None (Adobe
Reader’s default setting is Shrink to Printable Area, which is printer-dependent, and usually
~97% – but no such shrinking is needed for this manual).
!
!
!
!
!
!
!
!
!
!
!
!
!
!
! !!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
R
e
v
i
s
i
o
n
Date
By
Description
1
R
0
16 August 2018
JL
First Release

ComNav P4 Installation and Operation Table of Contents, List of Figures and Tables
Document PN 29010100 V1r0 - 5 -
Document)History)
Revision:)
Date:)
By:)
Description:)
1R0!
November!2018!
First!Release!

ComNav P4 Installation and Operation Table of Contents, List of Figures and Tables
Document PN 29010100 V1r0 - 6 -
Table of Contents
Welcome ......................................................................................................................... 2
About this Manual .................................................................................................................................... 3
Typefaces, Common Phrases and Terms .............................................................................................. 3
Manual Format ........................................................................................................................................ 4
Document History .................................................................................................................................... 5
Table of Contents........................................................................................................... 6
List of Figures ........................................................................................................................................ 12
List of Tables ......................................................................................................................................... 14
How Autopilots Work................................................................................................... 18
Basic Autopilot System .......................................................................................................................... 19
Autopilot Operation: Maintaining a Heading and Current Effects .......................................................... 20
Power Steer ........................................................................................................................................... 25
System Overview ......................................................................................................... 26
Control Head .......................................................................................................................................... 29
Signal Processor Unit ............................................................................................................................ 30
Compasses ............................................................................................................................................ 31
G2 and G2B GPS Compasses .............................................................................................................. 31
Fluxgate Compass ................................................................................................................................. 33
Magnetic Compass Sensor .................................................................................................................... 34
Magnetic Compasses ............................................................................................................................ 34
Other Compasses .................................................................................................................................. 35
Rudder Followers ................................................................................................................................... 35
Standard Rotary Rudder Follower and Rudder Linkage ........................................................................ 35
Heavy Duty Rotary Rudder Follower ..................................................................................................... 35
Jog Levers ............................................................................................................................................. 36
Rudder Angle Indicator (RAI) – 3” ......................................................................................................... 36
Rudder Drives and Interfaces ................................................................................................................ 38
CT7 Thruster Interface .......................................................................................................................... 38
Other Drive Boxes ................................................................................................................................. 39
Pumps and Drives ................................................................................................................................. 40
Other Equipment .................................................................................................................................... 40

ComNav P4 Installation and Operation Table of Contents, List of Figures and Tables
Document PN 29010100 V1r0 - 7 -
Installation............................................................................................................................... 43
Basic Requirements ................................................................................................................................................ 43
Steering System ...................................................................................................................................................... 43
Power Supply .......................................................................................................................................................... 43
Special Tools ........................................................................................................................................................... 43
Fasteners ................................................................................................................................................................. 43
Control Head ........................................................................................................................................................... 44
Electrical Connection ............................................................................................................................................... 44
Signal Processor Unit .............................................................................................................................................. 44
Compasses .............................................................................................................................................................. 45
Electrical Connection ............................................................................................................................................... 45
Magnetic Compass and Sensor .............................................................................................................................. 46
Rudder Follower ...................................................................................................................................................... 47
Rotary Rudder Follower ........................................................................................................................................... 48
Heavy Duty Rotary Rudder Follower ....................................................................................................................... 49
Other Equipment ..................................................................................................................................................... 49
Signal Processor Unit .............................................................................................................................................. 50
Wiring the SPU – General ....................................................................................................................................... 50
Connectors on the SPU ........................................................................................................................................... 50
Wiring the System ................................................................................................................................................... 52
Power Supply .......................................................................................................................................................... 58
Input and Output Connections ................................................................................................................................. 55
Jog Levers ............................................................................................................................................................ 55
Compasses ........................................................................................................................................................... 57
Rudder Follower ................................................................................................................................................... 57
Rudder Angle Indicators ....................................................................................................................................... 58
Drive Outputs ........................................................................................................................................................... 58
Reversing DC Motor Hydraulic Systems ................................................................................................................. 58
Linear Actuators or Mechanical Rotary Drives ........................................................................................................ 59
Shunt-Field Reversing Motors ................................................................................................................................. 60
Standard Four-Way Solenoid-Activated Hydraulic Valves ...................................................................................... 60
A.C. Solenoids ......................................................................................................................................................... 61
Azimuth Drives, Surface Piercing Drives and Jet Drives ......................................................................................... 62
External Alarm Output ............................................................................................................................................. 62
Power Failures ......................................................................................................................................................... 64
Speed Mode and Timing Outputs ............................................................................................................................ 65
Navigation Data ....................................................................................................................................................... 66
Signal Names .......................................................................................................................................................... 67
RS-422 Electrical Interface ...................................................................................................................................... 67
Typical RS-422 Signals ........................................................................................................................................... 68
RS-232 Electrical Signals ........................................................................................................................................ 69
LED Status Indicators .............................................................................................................................................. 69
Other Connections ................................................................................................................................................... 69
Post-Installation Checks .......................................................................................................................................... 69

ComNav P4 Installation and Operation Table of Contents, List of Figures and Tables
Document PN 29010100 V1r0 - 8 -
Getting Started ....................................................................................................................... 72
Autopilot Operations ................................................................................................................................................ 73
Power On/Of ............................................................................................................................................................ 73
Using the Control Head – LCD Screen and Buttons ............................................................................................... 75
Operating Modes and Menus .................................................................................................................................. 76
Advanced Operations ............................................................................................................................................. 77
Alarm Clear ............................................................................................................................................................. 82
System Setup Menu ............................................................................................................................................. 82
To Repair and Reset ............................................................................................................................................... 87
Connect GNSS (N2K) Compass to System ............................................................................................................ 88
Connect Rotary Follower Unit to System ................................................................................................................. 89
Magnetic / Fluxgate Compass and Rotary Feedback Flollower .............................................................................. 89
Connect Fluxgate Compass to the SPU .................................................................................................................. 90
For Non-ComNav Devices ....................................................................................................................................... 91
Network System Information ................................................................................................................................... 95
AP Network .............................................................................................................................................................. 97
SPU Dockside Menu ............................................................................................................................................. 100
Reset ..................................................................................................................................................................... 101
Vessel Type ........................................................................................................................................................... 101
Compass Setup ..................................................................................................................................................... 102
Drive Setup ........................................................................................................................................................... 102
Exit ......................................................................................................................................................................... 102
Alarm O/P (Alarm Output) ..................................................................................................................................... 102
Thrust MAX ............................................................................................................................................................ 102
Language ............................................................................................................................................................... 102
Setup Procedures .................................................................................................................................................. 103
Vessel Type ........................................................................................................................................................... 103
Drive Setup ............................................................................................................................................................ 104
Compass Setup ..................................................................................................................................................... 107
Analog Compass ................................................................................................................................................... 108
NAV1 Port .............................................................................................................................................................. 108
NAV1 or NAV2 Port for General NMEA0183 Compass ........................................................................................ 109
Bandwith of a NMEA Compass Connection .......................................................................................................... 110
Compass Setup On The Water ............................................................................................................................. 113
Compensation for Magnetic Deviation ................................................................................................................... 113
Magnetic Compass Sensor ................................................................................................................................... 113
Fluxgate Compass ................................................................................................................................................. 114
Compass Calibration ............................................................................................................................................. 115
Sea Trials .............................................................................................................................................................. 117
Sea Trials Procedures and Adjustments ............................................................................................................... 117

ComNav P4 Installation and Operation Table of Contents, List of Figures and Tables
Document PN 29010100 V1r0 - 9 -
Basic Operations ................................................................................................................. 122
Control Head LCD Screen and Buttons ................................................................................................................. 123
Operating the System ............................................................................................................................................ 125
Mode Menus .......................................................................................................................................................... 125
Rudder Angle Indicator .......................................................................................................................................... 127
Power On ............................................................................................................................................................... 128
Power Off ............................................................................................................................................................... 128
Standby Menu ....................................................................................................................................................... 129
Auto Menu ............................................................................................................................................................. 131
NAV Menu ............................................................................................................................................................. 132
Work Menu ............................................................................................................................................................ 133
Standby Menu ....................................................................................................................................................... 134
Station Lock ........................................................................................................................................................... 134
Default Turn ........................................................................................................................................................... 134
Compass Source ................................................................................................................................................... 134
Compass Cal (Compass Calibration) .................................................................................................................... 134
Backlight Level ...................................................................................................................................................... 135
Watch Alarm .......................................................................................................................................................... 135
Fishzag Time ......................................................................................................................................................... 135
Battery ................................................................................................................................................................... 135
Power Steer Mode ................................................................................................................................................. 135
Power Steer Menu ................................................................................................................................................. 136
Stdby/P.Str Limits (Power Steer Rudder Limits) .................................................................................................... 136
Auto/Nav Limits ..................................................................................................................................................... 137
RAI Offset .............................................................................................................................................................. 137
Auto Mode ............................................................................................................................................................. 137
Rudder Gain .......................................................................................................................................................... 138
Turn Rate ............................................................................................................................................................... 139
Parameter Set ....................................................................................................................................................... 139
Speed Trip Pt (Speed Trip Point) .......................................................................................................................... 140
Speed Source ........................................................................................................................................................ 140
ALC (Automatic Leeway Correction) ..................................................................................................................... 140
Thruster Assist and Gain ....................................................................................................................................... 140
Nav Mode .............................................................................................................................................................. 140
Nav Menu .............................................................................................................................................................. 142
Nav Source ............................................................................................................................................................ 142
XTE Limit (Cross-Track Error Limit) ...................................................................................................................... 142
WayPt. Arrival (Waypoint Arrival) .......................................................................................................................... 142
Correction .............................................................................................................................................................. 143
XTE Sense (Cross-Track Error Sense) ................................................................................................................. 143
Max Correction ...................................................................................................................................................... 143
Commanded Heading Displayed ........................................................................................................................... 144
Correction set to CTS – Steering a Direct Bearing ............................................................................................... 144
Correction set to XTE – Cross-Track Error Steering ............................................................................................ 145
Correction set to Both – Steering To/Along a Track .............................................................................................. 146
Alternate NAV Display ........................................................................................................................................... 148
Dodge .................................................................................................................................................................... 148
Jog Lever Turns ..................................................................................................................................................... 150

ComNav P4 Installation and Operation Table of Contents, List of Figures and Tables
Document PN 29010100 V1r0 - 10 -
Advanced Operations ........................................................................................................ 152
WORK Mode ........................................................................................................................................................ 153
Work Menu ........................................................................................................................................................... 156
Rudder Bias ......................................................................................................................................................... 156
Autotrim ................................................................................................................................................................ 156
Work Trip Pt. (Work Trip Point) ............................................................................................................................ 156
Rudder Scale (Rudder Scale Factor) ................................................................................................................... 157
Work Mode State ................................................................................................................................................. 157
Special Turns ....................................................................................................................................................... 157
U-Turn .................................................................................................................................................................. 158
Circle Turn ........................................................................................................................................................... 159
M.O.B. – Man Over-Board ................................................................................................................................... 160
Fishzag ................................................................................................................................................................ 161
Multiple Control Heads and Auxiliary Controller .................................................................................................. 162
Station Lock/Unlock ............................................................................................................................................. 162
Watch Alarm ........................................................................................................................................................ 163
Entering the Password ......................................................................................................................................... 164
Changing the Password ....................................................................................................................................... 164
Care and Maintenance ....................................................................................................... 166
Cleaning and Appearance ................................................................................................................................... 167
Protection of Wires and Cabling .......................................................................................................................... 167
Periodic Checks ................................................................................................................................................... 167
Fuse Replacement ............................................................................................................................................... 168
Appendices .......................................................................................................................... 170
Appendix 1 _____________________________________________________________ 171
NMEA 0183 Sentences Accepted and Transmitted by the Autopilot ................................................................... 171
Messages Accepted171 ....................................................................................................................................... 171
Messages Transmitted174 ................................................................................................................................... 174
Appendix 2 _____________________________________________________________ 175
Error Messages175 .............................................................................................................................................. 175
Appendix 3 _____________________________________________________________ 178
Diagnostic LEDs .................................................................................................................................................. 178
Appendix 4 _____________________________________________________________ 179
Upgrading Firmware ............................................................................................................................................ 179
Appendix 5 _____________________________________________________________ 180
General Specifications ......................................................................................................................................... 180

ComNav P4 Installation and Operation Table of Contents, List of Figures and Tables
Document PN 29010100 V1r0 - 11 -
Compass Safe Distances ...................................................................................................................................... 181
CE Compliance ...................................................................................................................................................... 182
Warranty Information ............................................................................................................................................. 183
Index ...................................................................................................................................................................... 187
User Notes and Settings ........................................................................................................................................ 190

ComNav P4 Installation and Operation Table of Contents, Lists of Figures and Tables
Document PN 29010100 V1r0 - 12 -
List of Figures
Figure 1 – Basic Autopilot System .................................................................................................................. 19
Figure 2 – Heading Change in AUTO Mode ................................................................................................... 22
Figure 3 – P4 System Block Diagram ............................................................................................................ 28
Figure 4 – Control Head .................................................................................................................................. 29
Figure 5 – The P4 SPU with Wiring and Diagnostic Covers Removed ........................................................... 30
Figure 6 – G2 GPS Compass ......................................................................................................................... 31
Figure 7 – Navigator G2 Display Head ........................................................................................................... 32
Figure 8 – Navigator G2 Distribution Unit ....................................................................................................... 33
Figure 9 – Fluxgate Compass ......................................................................................................................... 33
Figure 10 – Magnetic Compass Sensor .......................................................................................................... 34
Figure 11 – Externally Gimballed Magnetic Compass with Binnacle .............................................................. 34
Figure 12 – Rotary Rudder Follower ............................................................................................................... 35
Figure 13 – Heavy Duty Rotary Rudder Follower ........................................................................................... 36
Figure 14 – Jog Lever ..................................................................................................................................... 36
Figure 15 – External Rudder Angle Indicator - 3" Model ................................................................................. 37
Figure 16 – CT7 Interface ............................................................................................................................... 38
Figure 17 – Drive Boxes to meet all needs ..................................................................................................... 39
Figure 18 – Hydraulic Pump and Solenoid Value ........................................................................................... 40
Figure 19 – Cable Drives ................................................................................................................................ 40
Figure 20 – Continuous Running Electric Pump ............................................................................................. 40
Figure 21 – Rudder Follower Linkage Geometry ............................................................................................ 48
Figure 22 – SPU Connector Wiring Label ....................................................................................................... 51
Figure 23 – Typical Battery Connection to SPU ............................................................................................. 52
Figure 24 – Typical Battery Connection to Head ............................................................................................ 53
Figure 25 – Typical Battery Connection to Drive Boxes ................................................................................. 54
Figure 26 – Reducing Supply Voltage Losses ................................................................................................ 54
Figure 27 – Wiring Connections for SPU to N2K Networks ............................................................................ 55
Figure 28 – Wiring Connections for Jog Levers .............................................................................................. 56
Figure 29 – Wiring Connections for Four-Way Valves with Jog Levers .......................................................... 56
Figure 30 – Wiring Connections for Analog Compasses ................................................................................ 57
Figure 31 – Wiring Connections for Rudder Followers ................................................................................... 57
Figure 32 – Wiring Connections for Rudder Angle Indicators ......................................................................... 58
Figure 33 – Wiring Connections for Reversing DC Motors ............................................................................. 59
Figure 34 – Wiring Connections for Linear Actuators or Mechanical Rotary Drives ....................................... 59
Figure 35 – Wiring Connections for Shunt Field Reversing Motors ................................................................ 60
Figure 36 – Wiring Connections for Standard Four-Way Solenoid Valves ..................................................... 60
Figure 37 – Wiring Connections for Constant Running Electric Pump. .......................................................... 61
Figure 39 – Wiring Connections for A.C. Solenoids ........................................................................................ 62
Figure 40 – External Alarm, using SW'D B- Output ........................................................................................ 62
Figure 41 – External Alarm, using SW'D B+ Output ....................................................................................... 63
Figure 42 – External Alarm, SW'D B- Output – with Power Fail Option .......................................................... 64
Figure 43 – External Alarm, SW'D B+ Output – with Power Fail Option ......................................................... 64
Figure 44 – Typical NMEA 0183 Connections ................................................................................................ 66
Figure 45 – Typical NMEA 0183 RS-422 Transmission ................................................................................ 68
Figure 46 – Introductory Display ..................................................................................................................... 74
Figure 47 – Using the Control Head ............................................................................................................... 75
Figure 48 – Typical Work Mode Screen (Engaged) ........................................................................................ 78
Figure 49 –Work Mode Menu .......................................................................................................................... 80

ComNav P4 Installation and Operation Table of Contents, Lists of Figures and Tables
Document PN 29010100 V1r0 - 13 -
Figure 50 – A Typical Menu ............................................................................................................................ 81
Figure 51 – Set Vessel Type ......................................................................................................................... 104
Figure 52 – Set Compass Type .................................................................................................................... 107
Figure 52a – Using the Control Head ........................................................................................................... 123
Figure 53 – A Typical Menu .......................................................................................................................... 126
Figure 54 – Standby Button .......................................................................................................................... 128
Figure 55 – Power On Sequence .................................................................................................................. 128
Figure 56 – Standby Menu (pages 1,2 & 3) .................................................................................................. 134
Figure 57 – Typical Power Steer Mode Screen ............................................................................................ 136
Figure 58 – Power Steer Menu ..................................................................................................................... 136
Figure 59 – Typical Auto Mode Screen ......................................................................................................... 137
Figure 60 – Guidelines for setting Counter Rudder ...................................................................................... 138
Figure 61 – HI and LO Speed Icons (Left of Rudder Angle Indicator) ......................................................... 140
Figure 62 – Typical NAV Mode Screen (Normal Display) ............................................................................. 141
Figure 63 – Nav Menu, pages 1 and 2 .......................................................................................................... 142
Figure 64 – Steering with Correction set to CTS .......................................................................................... 144
Figure 65 – Steering with Correction set to XTE ........................................................................................... 145
Figure 66 – Response of Vessel to a Large Cross-Track Error .................................................................... 146
Figure 67 – Steering with Correction set to Both .......................................................................................... 147
Figure 68 – Typical NAV Mode Screen (Alternate Display) .......................................................................... 148
Figure 69 – A Dodge in Progress (in AUTO Mode) ...................................................................................... 149
Figure 70 – Vessel Track During a Dodge Manoeuvre in AUTO Mode ........................................................ 149
Figure 71 – Typical Jog Lever Activated Screen .......................................................................................... 150
Figure 72 – Typical WORK Mode Screen (Engaged) ................................................................................... 154
Figure 73 – WORK Mode Menu .................................................................................................................... 156
Figure 74 – Typical Special Turn Query ....................................................................................................... 157
Figure 75 – U-Turn Query ............................................................................................................................. 158
Figure 76 – U-Turn Vessel Path ................................................................................................................... 158
Figure 77 – Circle Turn Query ...................................................................................................................... 159
Figure 78 – Circle Turn Vessel Path ............................................................................................................. 159
Figure 79 – M.O.B. Turn Query .................................................................................................................... 160
Figure 80 – M.O.B. Turn Vessel Path ........................................................................................................... 160
Figure 81 – Fishzag Turn Query ................................................................................................................... 161
Figure 82 – Fishzag Turn .............................................................................................................................. 161
Figure 83 – Station Lock Icons on Main (Left) and AUX Control Head (Right) ............................................. 162

ComNav P4 Installation and Operation Table of Contents, Lists of Figures and Tables
Document PN 29010100 V1r0 - 14 -
List of Tables
Table 1 – Minimum Recommended Wire Gauges .......................................................................................... 50
Table 2 – Speed Mode and Timing Outputs .................................................................................................... 65
Table 3 – NMEA Signal Translation Guide ..................................................................................................... 67
Table 3a – Turning Off P4 System ................................................................................................................... 74
Table 4 – Vessel Type .................................................................................................................................. 104
Table 5 – Compass Types ............................................................................................................................ 112
Table 6 – Nav Mode Correction .................................................................................................................... 143
Table 7 – Fuse Replacement Guide ............................................................................................................. 168
Table 8 – NMEA 0183 Sentences Accepted by the P4 ................................................................................ 172
Table 9 - NMEA Sentence Priority ................................................................................................................ 173
Table 10 – Warning Messages ..................................................................................................................... 175
Table 11 – Error Messages ........................................................................................................................... 176
Table 12 – Critical Error Messages ............................................................................................................... 176
Table 13 – Diagnostic LEDs ......................................................................................................................... 178
Table 14 – General Specifications ................................................................................................................ 180
Table 15 – Compass Safe Distances ............................................................................................................ 181
Table 16 – User Settings .............................................................................................................................. 191
!

ComNav P4 Installation and Operation Table of Contents, Lists of Figures and Tables
Document PN 29010100 V1r0 - 15 -

ComNav P4 Installation and Operation
Document PN 29010100 V1r0 - 16 -
Introduction

ComNav P4 Installation and Operation
Document PN 29010100 V1r0 - 17 -

How Autopilots Work
Document PN 29010100 V1r0 - 18 -
How Autopilots Work
The purpose of this introductory section is to briefly describe what an autopilot does and some of
the things you should expect when using an autopilot with your boat.
Manual Steering
Every vessel has unique dynamics, which depend on its design, shape and dimensions, as well as
current speed, loading, and sea conditions. The net result is that every boat (or rather, every
unique boat design) “steers” in a unique way.
To understand what an autopilot does when it is steering your vessel, it is helpful to think for a
moment about steering a boat by hand.
• When you are holding the boat on a given Heading, you know from instinct and
experience how much rudder to apply, and how fast to apply it, to keep the boat
on-course. Corrections are usually just a small, quick movement of the helm to one side, then
back to the dead-ahead position.
• You won’t always try to correct when the boat rolls or accelerates off a wave,
especially in heavy seas – because when the boat rolls back the other direction, it will usually
come right back on-course.
Instead, your experience reminds you to allow the boat to yaw those necessary degrees on
either side of the Heading, to reduce the fight.
• To turn the boat to a new Heading, instinct and experience again remind you how
much rudder to use, and how fast, to get the boat turning at your normal rate of steer.
If the boat is not turning as rapidly as you want (for example, with a cross- or cross-current
holding back the bow), you slightly increase the amount of rudder.
On the other hand, if the boat is turning too fast, you reduce the applied rudder a bit.
You then gradually reduce the applied rudder, as the boat approaches the desired Heading.
You might even put the helm over opposite for a moment, to stop the boat swing more quickly –
in order to come to the desired Heading without overshoot.
The single most basic purpose of an autopilot is to control the vessel the same as a human operator
would … to let the boat “work with the seas”, yet still maintain as straight a Track as possible in the
current conditions, on the desired Heading or Course.
The P4 Autopilot System uses the latest generation of ComNav’s carefully-designed, well-proven
steering control algorithms, which are based on many years of designing and manufacturing
autopilots.
There are a number of parameters used in the steering algorithms, collectively referred to as
“Steering Parameters.” The P4 Autopilot system has been tested on a wide variety of boats, of
different types and sizes. The default settings for the Steering Parameters are average values
derived from that testing, and provide a good starting place for most boats.
During sea trials, and later on normal operation, you may want to adjust some of those values, so
that they better match your boat’s unique design dynamics.
However, the information in this section can be applied in general to any ComNav autopilot, and is
not necessarily specific to the P-Series.
ComNav P4 Installation and Operation

How Autopilots Work
ComNav P4 Installation and Operation
Document PN 29010100 V1r0 - 19 -
Basic Autopilot System
Figure 1 is a block diagram of the major components of an autopilot system.
COMPASS
READS THE VESSEL'S
ACTUAL HEADING AND
SENDS IT TO THE SPU
PROCESSOR (SPU)
CALCULATES THE RUDDER
POSITION NEEDED TO STEER
THE VESSEL ON THE DESIRED
HEADING, AND CONTROLS THE
STEERING SYSTEM
ACCORDINGLY
STEERING SYSTEM (ACTUATOR)
[HYDRAULIC RAM OR ELECTRIC MOTOR
WHICH IS MECHANICALLY CONNECTED
TO THE RUDDER]
MOVES THE RUDDER IN RESPONSE TO
CONTROL SIGNALS FROM THE SPU
RUDDER FOLLOWER UNIT (RFU)
[MECHANICALLY CONNECTED TO RUDDER]
MEASURES RUDDER POSITION AND SENDS
IT TO THE SPU
NAVIGATION DEVICES
[OPTIONAL]
SUPPLY NAVIGATION
INFOMRATION TO THE SPU
IN NMEA 0183 FORMAT
CONTROL HEAD
DISPLAYS STATUS AND HEADING
INFORMATION FROM THE SPU, AND
ALLOWS THE OPERATOR TO INPUT
STEERING COMMANDS & OPERATING
PARAMETERS
Figure 1–Basic Autopilot System
The Compass indicates the direction in which the boat is pointed, often referred to as the
Actual Heading. Depending on the type of boat and installed equipment, the Compass may
be a magnetic compass, an electronic fluxgate compass, a gyroscopic compass, or a GPS
Compass.
•A reliable compass is absolutely vital to the autopilot; without a trusted compass, the
autopilot has no way of knowing where the boat is, or which way it is headed.
The actual heading is fed electronically from the Compass to the Signal Processor Unit
(SPU), which is the heart of the autopilot. The SPU contains the microcontroller(s), electronic
hardware, and the sophisticated control software necessary to steer the boat on any desired
Heading.
The Control Head, normally located in the wheelhouse, is the interface between the vessel’s
operator and the autopilot. The Control Head displays information about what the autopilot is
doing, and it has various controls (buttons and/or knobs) that allow you to give commands to
the autopilot.
OR IN NMEA2000
FORMAT

How Autopilots Work
ComNav P4 Installation and Operation
Document PN 29010100 V1r0 - 20 -
The final part of the picture is the Steering System. In order for the autopilot to steer the boat,
there must be a steering system capable of moving the rudder independently of the ship’s
helm. This might be a hydraulic ram that is connected to the rudder post or tiller quadrant, or
an electric motor connected to the steering cables.
However, no matter what type of steering system the boat uses, electronic signals from the
SPU tell the system to move the rudder, when needed – how far and in which direction.
Your autopilot may also have a Rudder Follower Unit (also called a Rudder Feedback Unit, or
just “RFU”), a device that tells the SPU what position the rudder is in at any given time.
Autopilot Operation
Maintaining a Heading: AUTO Mode
With a ComNav Autopilot, following a Track or Course that you want to be on is very simple:
• Set the autopilot into AUTO mode.
• Using the Control Head, input the Heading you want the autopilot to follow.
• The autopilot then moves the rudder (as required) to initiate and keep the
vessel on that Heading … just like you would if you were steering manually.
Here’s how it works:
The steering control algorithms running in the firmware on the SPU’s microcomputer are
constantly comparing – multiple times per second – the boat’s actual Heading (as indicated
by the Compass) to the desired Heading you have input.
If there is a difference, the algorithms then calculate how much to move the rudder, to
bring the boat back onto the desired Heading. The amount of corrective rudder
movement is based on:
• How much the Headings differ.
• How long there has been a difference and by how much.
• How rapidly the difference is changing.
Here is an example which illustrates how the autopilot maintains a Heading in AUTO
mode. Imagine the boat is a few degrees off-course to Port:
• The SPU will signal the steering system to move the rudder to Starboard,
by a few degrees.
How many degrees the rudder moves depends on the type of vessel, and its
dynamics (which you have specified and tested when you set up the autopilot).
Note: On a P4 Autopilot with an RFU, the SPU verifies that the rudder
has moved, by reading its position from the RFU.
• The boat begins to turn to Starboard.
• As the boat turns, the difference between the desired and actual
Heading gets smaller, and as it does, the SPU then starts to ‘back off” the
rudder – i.e., move it back to centre – so that the boat does not overshoot the
desired Heading.
• If the boat isn’t coming back on-course very quickly, the SPU’s
algorithms will not back the rudder off right away, and might even move the
rudder a bit farther to Starboard for a while.