True North Revolution User manual

Revolution™ Compass Kit
User’s Guide

True North Technologies Document No. 1554-B
Revisions
November 2002, Rev A, First Release
March 2003, Rev B, New J2 Wiring Instructions
Copyright © 2002 True North Technologies LLC
Revolution™ is a trademark of True North Technologies LLC
Contact:
True North Technologies
Two Clock Tower Place, #335
Maynard, MA 01754
Voice: 978-897-5400
Fax: [phone]
Web: www.tntc.com
Email: [email protected]

True North Technologies Document No. 1554-B
Contents
Introduction ...........................................................................................................1
Contents of the Kit ................................................................................................1
Revolution Compass .........................................................................................2
Palm PDA and Carrying Case...........................................................................2
Revolution Software CD ....................................................................................3
Cables and Batteries .........................................................................................3
4-Wire PDA to Compass: True North P/N 1570............................................3
4-Wire PC to Compass: True North P/N 1540 ..............................................4
8-Wire Compass Interface (Optional): True North P/N 1580 ........................4
Palm Hot Sync® Cradle: Palm P/N P10700U...............................................4
Features................................................................................................................5
Compass Features ............................................................................................5
PDA Features....................................................................................................5
PC Software Features .......................................................................................6
Getting Started......................................................................................................7
Starting Up the PDA ..........................................................................................7
How the PDA is Prepared..............................................................................7
PDA Battery Power........................................................................................7
Calibrating the Touch Screen and Setting Local Time...................................8
Connecting the Revolution.............................................................................8
Verifying Correct Operation ...........................................................................8
Capturing Data.............................................................................................10
Getting to Know the PC Software....................................................................11
System Requirements .................................................................................11
System Recommendations..........................................................................11
Revolution Software.....................................................................................12
Palm Desktop Software ...............................................................................13
Preliminary Compass Evaluation.....................................................................13
How the Revolution Compass is Prepared ..................................................13
Pitch and Roll Check ...................................................................................14
Magnetometer Check ..................................................................................14
Dip Angle Check ..........................................................................................14
Using the PC Revolution Program ......................................................................15
Running the Revolution Software for the First Time ........................................15
Description of the Software Main Screen ........................................................17
Compass Installation...........................................................................................17
Location...........................................................................................................17
Mounting .........................................................................................................18
Wiring to the Internal Connector (J2)...............................................................18
Selecting RS-232 or RS-485 ...........................................................................20
Connecting the PDA While the Compass is Operating....................................20
Calibrating the Compass.....................................................................................20
Capturing a Vertical Reference .......................................................................21
Collecting Data in Continuous, Circular Motion ...............................................22
Collecting Discrete Samples when Stopped....................................................23
Applying Calibration Results ...........................................................................24

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Introduction
The Revolution compass combines a precision 3-axis solid-state magnetometer
and a rugged 2-axis electrolytic tilt sensor that have been factory calibrated to
provide accurate heading and tilt measurements. The unit has been verified for
accuracy at room temperature in an environment free from magnetic, electrical,
and mechanical disturbances. Using the PDA provided, the compass can be
immediately tested in an out-of-doors location away from any ferrous material
and isolated from severe vibration.
A good first test is to hold the compass steady at different attitudes (heading,
pitch, and roll), take readings, and verify that the horizontal field strength remains
roughly the same for different orientations. Refer to the section on Verifying
Correct Operation in Starting Up the PDA for instructions on how to take
readings. Be careful to keep the PDA and 9V battery away from the compass, as
they can affect the readings. Expect to see some variation in the horizontal field
strength, but it should be less than one or two percent if the compass is steady
and tilt is less than 20°.
Before installing the Revolution, make note of the dip angle measurement and
compare it to the published value for your location. The two values should be
very close, usually within 0.5°. It is also a good idea to capture and save a
vertical reference as described in the section on Calibrating the Compass. After
the compass is mounted in-situ, this reference is used to partially compensate for
any local permanent magnetism (hard-iron) that may be present.
Contents of the Kit
The Revolution compass kit contains the following primary items described in
detail in this section:
•Revolution Compass
•Palm™ PDA and Carrying Case
•Revolution Software CD
•Cables and Batteries

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Revolution Compass
The Revolution represents the state of the art in magnetic compassing. It
consists of a PC card housed in an ABS enclosure. The base of the enclosure
has 4 mounting holes for permanent installation. Only brass or non-magnetic
stainless steel screws should be used. Connection to the compass may be
made via the RJ12 connector (for the PDA or PC) or by the 8 pin header (for
system wiring). See the diagrams included with the cables.
Palm PDA and Carrying Case
The Palm m105 features 8MB of memory, a touch screen graphical display, and
an integral serial RS-232 interface. It is pre-loaded with True North’s Compass
interface program. While the compass is in-place and without disconnecting
system wiring, the PDA can be temporarily connected via the RJ12-style modular
jack. This allows easy access during installation for calibration and tuning. It also
provides a valuable diagnostic port and can be used for an auxiliary read-out
when needed. In
situations where a fixed
installation is not
desirable, the RJ12
connection can be used
exclusively.
The carrying case holds
the PDA, compass
interface cable, a 9V
battery for compass
power, and two extra AA
batteries for the PDA.
There’s extra room
available in several
pockets.

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Revolution Software CD
This is a mini, business-card style CD with both the Revolution interface software
for a Microsoft Windows PC and software for the PDA. When the CD is loaded
into a CDROM drive, the display shown in Figure 1 will automatically appear if
the auto-run feature is enabled.
Figure 1
Cables and Batteries
Two AAA batteries are loaded in the PDA, and there are 2 extras in the PDA
carrying case. A 9V battery for compass power is connected to the PDA cable in
the carrying case.
The following cable assemblies are included:
4-Wire PDA to Compass: True North P/N 1570
8 ft. cable with Palm connector and 9V battery strap going to 6-pin RJ12 plug.

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4-Wire PC to Compass: True North P/N 1540
8 ft. cable with DB9F connector and 9V battery strap going to 6-pin RJ12 plug.
This cable is shown in Figure 2.
Figure 2
8-Wire Compass Interface (Optional): True North P/N 1580
8 ft. cable with 8-pin, 0.1” MTA connector going to open wire pairs (not
terminated). Used for both RS-232 and RS-485 signals. This cable is shown in
Figure 3.
Figure 3
Palm Hot Sync® Cradle: Palm P/N P10700U
Connects PDA to PC. Included with Palm m105 retail box.

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Features
Compass Features
The Revolution compass is a third-generation, strap-down device that delivers
high accuracy for its small size, low cost, and low power consumption. It provides
both RS-232 and RS-485 communication links. For battery operation, a low-
power standby mode is incorporated to reduce required current to 1mA. Wake
up from standby requires only 1 millisecond.
Additional features of the compass include:
•Run (continuous) or Sample mode operation
•NMEA 0183 output data format with the following available sentences:
⇒HDT (True heading – standard sentence)
⇒HDG (Heading, deviation, and variation – standard sentence)
⇒XDR (Transducer data: pitch, roll, magX, magY, and magZ –
standard sentence)
⇒HTM (Heading, tilt, and magnetic field – proprietary sentence)
⇒NCD (Normalized compass data – proprietary sentence)
⇒CCD (Conditioned compass data – proprietary sentence)
•Output data available:
⇒Heading, pitch, and roll
⇒Magnetometer X, Y, Z, and calculated total field
⇒N, E, H, and V - normalized magnetic field components
⇒Magnetic inclination (dip angle)
•Angles in degrees (0.0 to 359.9°), mils (0 to 6399), milliradians (0 to
6282), or 16-bit integer (0 – 65535)
•Tunable alarm on H field deviation in Run mode
•Selectable averaging time in Sample mode
•Separate magnetic and tilt IIR single-pole filters in Run mode
•Tunable heading filter in Run mode for quick response in hand-held
applications where fast movements should be ignored
•Magnetic field measurement range: ±1.6 G (gain 100)
•Magnetic field measurement sensitivity: 0.3 mG (30 nT, gain 500)
•Serial EEPROM for calibration coefficients and setup parameters
PDA Features
The Palm PDA is a convenient service and evaluation tool that can also be used
for routine data acquisition tasks. It is used to perform the calibration procedure
required to compensate for local hard and soft iron, to change compass tuning
parameters, and to capture and store compass measurement data. For stand-

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alone operation, the serial interconnect cable attaches to a 9V battery that can
power the compass for over 500 hours (3 weeks) of continuous operation
(standby mode). For servicing a compass attached to a host computer, it can be
plugged in without disconnecting the system wiring. Calibration, tuning, and
capture functions can be performed without affecting the host.
Additional features of the PDA software are:
•Database of calibration, tuning, and capture data that can be transferred
to a PC or laptop using Hot Sync
•A single PDA can be used with more than one compass. Stored data
automatically tagged with compass device ID
•Graphical user interface layout and navigation similar to what is used with
PC software (Revolution PC program)
•Serial port hardware is turned off so that compass can automatically enter
low-power standby mode when measurements are not needed. Also
reduces PDA battery drain
•Straightforward calibration procedures minimize required user interaction
and generate optimal compensation coefficients
PC Software Features
The Revolution PC program is designed to run on most Microsoft Windows
platforms: 95, 98, NT, 2000, ME, and XP. There are two main components:
•A Visual Basic program (Revolution.Exe) that provides the graphical user
interface, database, and logging functions, and
•A windowless ActiveX control (Compass.Ocx) that implements the
compass serial interface, calibration functions, and Palm PDA data
conversion routines.
The ActiveX control can be used separately from the Revolution PC program to
simplify the task of integrating the compass into an end-user system. It provides
methods for reading and writing parameters; for reading, parsing, and converting
NMEA sentence data; for performing hard and soft iron calibration functions, and
for converting a PDA database file to tab-delimited text records. It also maintains
a text log of communication between the PC and compass that can be read by a
host application.
Functions provided by the Revolution PC software are:
•Cockpit attitude display of heading, reciprocal heading, pitch, and roll
•Display and capture NMEA sentence data
•Modify Revolution operating parameters
•Perform hard and soft-iron calibration procedures
•Provide electronic compass deviation table
•Transfer PDA data using HotSync® manager, then convert to text files
•View and maintain communication logs

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Getting Started
Starting Up the PDA
How the PDA is Prepared
We unpacked and tested the PDA and cable assembly at the factory. Two AAA
batteries are already installed. Batteries in the carrying case pouch are extras.
The PDA touch screen has been calibrated, and the time is set to USA Eastern
Standard Time. The Revolution Compass program is already loaded, but a user
account has not been assigned for the HotSync operation.
We also loaded the freeware program GeoMagInfo Version 1.1. For a given
longitude and latitude, this program calculates magnetic declination (variation),
inclination (dip angle), and total magnetic field based on the year 2000 USGS
models. This program is unrelated to the Revolution compass program and can
be deleted if no longer desired.
Before using the PDA extensively, it’s probably a good idea to recalibrate the
touch screen, set the time to your local time zone, and verify that the PDA
batteries have adequate charge remaining. You may also need to adjust the
screen contrast, and in low-light conditions, you may need to turn on the display
backlight. If you have not used a Palm PDA before, familiarize yourself with the
basic features of the device by skimming Getting Started.pdf on the Palm
Desktop Software CD.
You will need to install the Palm Desktop Software on your PC or laptop prior to
performing a HotSync operation to transfer PDA data to the PC. See Getting
Started.pdf on the Palm Desktop Software CD for detailed instructions. You can
install it either before or after the Revolution program is installed.
Once the Palm Desktop Software is installed, you can use the Revolution
program to initiate a HotSync operation. Any compass data captured on the PDA
will automatically be transferred to the PC or laptop. The Revolution program
finds the data in a file named Compass.pdb, converts it to a tab-delimited, ASCII
text format, and archives the raw data file in a separate folder.
PDA Battery Power
Turn the PDA on by pressing the power button
located at the top center of the device. You
should see the Application Launcher screen with
the Compass category as shown in Figure 4. Tap
the Home icon (picture of a house) to see the
Application Launcher screen if it is not already
shown. Continue tapping the Home icon to
change categories.
Figure 4