CompuTracker Corporation has used its best efforts in preparing this manual and the instructions contained herein. CompuTracker Corporation makes no warranty, expressed or implied, for the use or misuse of this manual and assumes no responsibility for any errors or omissions in this manual. CompuTracker Corporation shall not be liable in any event for incidental or consequential damages in connection with, or arising out of the use of this manual or the information contained herein. The information in this manual is subject to change without notice.

No part of this publication may be reproduced or transmitted in any form or by any means electronic or mechanical, including photocopying and recording, for any purpose other than the purchaser's personal use, without the written permission of CompuTracker Corporation.

CompuTracker and GPS/Datalogger are trademarks of CompuTracker Corporation

DOS, Windows, Windows 95 and Excel are trademarks of Microsoft Corporation.

Lotus and Lotus 1-2-3 are trademarks of Lotus Corporation.

CompuTracker Corporation,

1517 Commercial Park Drive,

Lakeland FL 33801, U.S.A.

Telephone: +1 (727) 781-3923

WATS toll free: 1-888-464-5324

Copyright 1997 by CompuTracker Corporation All rights reserved

Author Paul Evans for CompuTracker Corporation.

29^th January, 1998. Revision 2. Printing 1.

This manual was prepared using Microsoft Word 97 Professional and Times New Roman font.

Caution! This product is not to be used as the sole means of navigation for any vehicle whether manned or unmanned. This product is not to be used in conjunction with any life support equipment. Position fixes are generated subject to the limitations of Selective Availability (S/A) as imposed by the U.S. Department of Defense.

Thank you for the purchase of your CompuTracker GPS datalogger. The datalogger is a low cost, compact unit which can be fitted to vehicles and will record the vehicle's location into solid-state flash memory. A total of nearly 10000 data points may be recorded at a maximum rate of once per minute. The rate at which recording occurs is proportional to the amount of vehicle movement.

Hook up to the vehicle is simple. The unit can be connected using either polarity and with an input voltage of from 8 to 40V DC or AC. An ignition switched power circuit should preferably be used so that the unit is off when the vehicle is off. However, leaving the unit running while the vehicle is stationary for long periods will not waste memory space, merely consume power. The power cable supplied may have red and black wires - but the polarity is still not important, your unit will work with power connected either way around. When power is applied, the red light (LED) will light after about 2 seconds and will flicker when valid position data is being received. Do not attempt to view the LED for valid data while driving the vehicle.

There are several variants of power cable with differing uses:

• Mobile, power only (standard configuration). A two wire power cable which consists of an 8 pin connector with two power wires and a DC accessory connector. [P/N CTDL-5000-P]
• Mobile, power & waypoint marking (mobile supervisory role). A cable which consists of an 8 pin connector with two power wires, a DC accessory connector and a (RED) waypoint pushbutton. [P/N CTDL-5000-W]
• Base, A.C. powered (office data management). A cable which consists of an 8 pin connector, wall transformer power supply, waypoint pushbutton, dump pushbutton and serial cable. [P/N CTDL-5000-S]
• Base, D.C. powered (roving data management). A cable which consists of an 8 pin connector, a DC accessory connector, waypoint pushbutton, dump pushbutton and serial cable (6 feet). [P/N CTDL-5000-R]

Place the unit in the vehicle and attach by using the optional power cable with waypoint button [P/N CTDL-5000-W]. Drive the vehicle over the route that will normally be driven. When at the waypoint location (bus stop or warehouse, etc.), briefly press the waypoint (RED) button. The unit will immediately store that location as a waypoint (provided that good position fixes are being received - see notes later). When data is retrieved from the unit, waypoints will be stored as special points and stored temporarily into the file waypoint.dat and may be stored for later retrieval as a file with a given name.

When the GPS/Datalogger is running, the serial port will echo the GPS receiver output at the same time as the unit is processing data. This data output may be connected to other on-board systems removing the need for another GPS receiver to be running in the vehicle. This output may be connected to PC mapping systems, autopilots, etc. The data is at RS-232 levels in 9600bps, 8, N, 1 format.

The unit can be left in the vehicle or removed for later analysis. The unit should be powered up and the PC connected to the serial port by using the special download cables (CTDL-5000-R or CTDL-5000-S].

With the PC connected to the datalogger start the retrieval program by running TRACK.EXE. From the opening menu you may choose to download data from the logger, leave the program or do statistical analysis of the recorded track, amongst other functions.

The program has been designed to be simple and easy to use. The choice of DOS as an environment was deliberate - the program should run on everything from an XT or AT to a state-of-the-art PC.

Once data has been retrieved to the PC a file called LOGFILE will be present. This file was designed to be easily readable by applications. If Microsoft Excel is to be used, a file called XFILE will automatically be generated when a Data Generate function is performed.

The page header displays the following key elements:

Program name, program version and date of issue.

Corporate source.

The current logfile in use (may be LOGFILE the default, or one selected from the logfile data area.

Time. Time in seconds which is being used for exception analysis.

Threshold. Distance in feet which is used during exception analysis to maintain stationary status.

Waypoint file in use. This may be either WAYPOINT.DAT or one selected from the waypoint data area.

Zone. The time zone in use with hours difference from GMT / UTC being shown.

Status. Indicates which critical functions have been performed since this running of the program. D indicates a Data Generate has been performed. G indicates a Get data from the logger has been performed.

Name. Indicates the vehicle or personal ID of the current data in use.

Type. Indicates whether the data is for a person (P) or vehicle (V).

When the program is started the following main menu is displayed:

Datalogger data retrieval program. v1.09 29th January, 1998. [track.exe]

Written by Dunedin Marine Systems for CompuTracker Corporation

Logfile in use: Time: 300 Threshold: 300 '

Waypoint file in use: Zone: -5 EST Status:

Name: Type:

Enter:

D(ata) generate (Waypoints, Excel, Statistics / Exceptions)

E(xit) program

G(et) data from datalogger

L(ogfile) data

O(ff time) analysis

Proxi(M)ity to waypoints

P(rint) functions

Q(uit) program

R(ecords) - Exceptions, Vehicles, Personnel

T(ime) offset change {temporary}

W(aypoint) file data

e(X)it program

Choice?

The records option is used to select particular data about exceptions, vehicles or personnel. For vehicles or personnel the data is the timesheet which indicates the normal hours used. Timesheets can be configured for every 15 minute period through the working day and can indicate on time, off time and overtime. Editting of this data is best performed by using a text editor on the file \computrk\units.dat. An explanation of the format of the file is given at the top of units.dat.

The records may be scanned by pressing enter, selected by using S or quit from by using Q.

Off time analysis cannot be performed without first selecting a vehicle or personal timesheet.

The time offset change function can be used to temporarily change the offset from GMT/UTC which is used by the program. This is useful when tracks are in other time zones from that at the base and local time is required in a report. This setting is only temporary whilst the program is running. The default startup time offset can be permanently changed by editting the file TRACK.CFG.

When the Get option is used, the following screen is displayed:

Datalogger data retrieval program. v1.09 29th January, 1998. [track.exe]

Written by Dunedin Marine Systems for CompuTracker Corporation

Press Dump (black) button to get data from logger

Pressing the black button on the datalogger will result in the datalogger dumping data. The data will be rapidly displayed on the screen as it is downloaded. If the unit is not receiving position fixes the black button should be pressed and held until the red LED flickers and then released. While the unit is downloading data the red LED will rapidly flicker.

If the Proximity option is selected the following screen is displayed:

Datalogger data retrieval program. v1.09 29th January, 1998. [track.exe]

Written by Dunedin Marine Systems for CompuTracker Corporation

Please wait .... analyzing waypoint proximity.

201233, 2522.441, 082120.300 near to waypoint 1 [215ft]

Press Enter to continue

All the data points which are close to any of the waypoints are displayed.

When the program is stopped by using Exit, Quit or eXit, the following screen is displayed.

Datalogger data retrieval program. v1.09 29th January, 1998. [track.exe]

Written by Dunedin Marine Systems for CompuTracker Corporation

Enter:

D(ata) generate (Waypoints, Excel, Statistics / Exceptions)

E(xit) program

G(et) data from datalogger

L(ogfile) data

O(ff time) analysis

Proxi(M)ity to waypoints

P(rint) functions

Q(uit) program

R(ecords) - Exceptions, Vehicles, Personnel

T(ime) offset change {temporary}

W(aypoint) file data

e(X)it program

Choice?

Program finished - returning to DOS

When the Load option is selected the following screen will be displayed:

Datalogger data retrieval program. v1.09 29th January, 1998. [track.exe]

Written by Dunedin Marine Systems for CompuTracker Corporation

Enter unit ID:

File loaded successfully

Press enter to continue

The unit ID is entered and the relevant file (if it exists) is recovered. This file may then be manipulated using the main menu file options.

Data will remain stored in the unit indefinitely. Several trips may be retained in memory, but data is best downloaded and deleted to avoid memory filling up. To delete data, power up the unit using a power cable which has both the RED and BLACK buttons. Press and hold the two buttons at the same time until the LED next flickers. If the serial port is connected to a terminal or PC the message "Logfile deleted" will be seen.

While it's nice to use custom programs to manipulate and analyze data, this can be clumsy and awkward to get into presentations, etc. The power of using office tools is that the tool developer has done all of the platform, operating system, data engine and display work for you.

Also, as computer technology improves, the tool developer will continue to support the same data formats and macros - your data and what you did to it will remain useable. However, older formats may need to be translated by the program in use, but this normally done automatically at the press of a mouse button.

Supplied with the datalogger is a file called LOG1.XLS - this is a Microsoft Excel spreadsheet which runs several pre-defined macros. It is a simple file which demonstrates the power of this approach by displaying a track from a log file and makes several calculations which may be displayed as slides in a presentation, for example. For this to function TRACK will have generated XFILE automatically, WFILE if there are any waypoints recovered from the datalogger and OFFFILE if an employees timesheet has been selected.

Start Excel from your desktop and open file LOG1.XLS. Then press CTRL-E. This will open and import data from XFILE, calculate distance covered and plot an automatically scaled graph of the vehicle track.

By pressing CTRL-W the most recently selected waypoint file will be displayed.

By pressing CTRL-Q the off time track will be displayed on top of the complete vehicle track. The original track shows the whole track covered, the off time track shows the proportion of the vehicle track which was outside the normal working hours of the driver.

Note: GPS receivers and the datalogger are not affected by magnetic fields and may be used next to strong magnetic fields without any operational problems.

Do not place the GPS antenna next to fluxgate or conventional magnetic compasses. The antenna has a magnetic mount which is very powerful and can be used for attachment to steel body panels.

Do not place the GPS antenna near computers or computer magnetic discs.

Drivers - Drivers must be briefed to NOT attempt to monitor the unit LED or serial port data whilst driving the vehicle. The drivers eyes should be on the road at all times.

When the unit is first powered up there is a short pause and then the red LED should light indicating that the microprocessor is running correctly. The last positional data is held in the GPS receiver by a built-in battery supply. If the GPS antenna is reasonably located, the receiver should achieve lock and beginning flashing the red LED every second after about 15 seconds of operation. If the red LED does not flash after this short period then the antenna is either screened from the satellites, the GPS system is "down" or the internal battery is dead. The unit should be left running and will achieve satellite lock if at all possible.

If the unit continues not to achieve satellite lock in a relatively short period the reason(s) should be investigated.

In some vehicles power is continuously applied from the DC accessory socket (cigarette lighter outlet) except for when the ignition circuit is used to start the engine. This results in momentary loss of power which causes a restart of the unit. This is notable on many Ford vehicles (as a "feature") and can also occur on vehicles with batteries in poor condition or in cold weather. This will not affect use of the unit but will result in slightly slower logging starts.

When GPS signals are lost the unit "freezes" recording and will start counting off towards the next log point only when signals are regained, thereby saving memory and extending recording time.

If the waypoint button is pressed the current location is immediately stored. Important - if the unit is not receiving position fixes at the time the next good fix is logged. This may be some distance from the intended waypoint. In vehicles where the power source is switched the operator must press the waypoint button upon arrival at the correct spot before turning the vehicle off.

If the unit remains stationary datalogging stops until movement begins again (sometimes selective availability may cause datalogging to occur but only very infrequently and will not effect recovery of data or exception analysis).

When the data memory is filled up (10,000 points or so) data logging stops and previously recovered data is not lost or over-written. Once data has been deleted from the unit all of logging memory is made free for use again.

Some customers have erroneously concluded that their receiver doesn't work if they do not get a position fix after only a couple of minutes. Let's just look at why sometimes fixes appear quickly and sometimes not.

Firstly, the GPS receiver is exactly that - just a receiver. It starts out not knowing where on earth it is. After about 28 seconds it will know from any ONE of the satellites what the date and time is (the overall data rates on GPS are very slow). It will then search around trying each one of the satellite codes (there are 24 of them) in an attempt to get good signals from FOUR satellites. This may take many minutes in this first attempt.

Some receivers such as that used in the datalogger have an on-board real time clock. This speeds up the time to first fix (TTFF) because the receiver does not have to wait to be told the time by a satellite. Of course, if the receiver has been switched on for the first time since a back-up battery was connected this clock will be wrong, but will get corrected within 28 seconds. Some other receivers have a real time clock and an on-board Lithium battery. Once these get a good time setting they will remember time almost indefinitely.

All receivers need a supply of 3V from a Lithium battery to maintain the almanac data in memory.

It takes a full 15 minutes to receive the almanac from the satellites and store it in RAM. This allows the receiver (once it knows the time and date) to predict which satellites are going to be visible to it when it is switched on next. Some fine tuning detail called the ephemeris is also downloaded and stored in the receiver's memory. Next time the receiver is turned on AND if the satellite signals are good, it will obtain a fix much more quickly. HOWEVER, if the receiver has moved significantly over the ground while switched off the almanac will predict the wrong satellites in view and will possibly panic after several minutes and go into the full sky search routine. A sky search is basically a random walk through the satellite IDs until one is found. This process continues until there are enough being tracked to derive a fix. This is a random process, so a fix might be derived in 30 seconds or after 5 minutes. It is therefore quite important to try to maintain power to the receiver's memory so that the almanac is not lost. This is taken care of inside the datalogger by use of an internal battery.

Put simply: if the receiver is new, has lost RAM battery backup or has moved a distance of more than 300 miles while switched off, it may take several minutes to get a fix. Subsequent warm starts should take between 15 seconds and 4 minutes to obtain a fix, depending on system geometry. With a real-time clock present on the GPS receiver board, this time may be as low as 12 seconds (datalogger test result).

Some notes about accuracy:

The accuracy of the position derived in the GPS receiver is dependent on the following factors:

The S/A can be as great as 100m (300ft) and the rate of change is limited to 5m/s.

Conclusion: GPS receivers are not born equal and small, low cost receivers cannot be used as accurate position sensors or for navigation in confined spaces. In fact, most of the time in good coverage areas, LORAN-C will produce more reliable position fixes. GPS may be "high tech", but it depends on moving reference points which need continuous updating by the ground command stations. It is very possible for GPS fixes to be very wrong. Always use with caution!

GPS is a "look down" system which was optimised for best resolution in the Earth plane. This means that GPS is at it's worst in determining altitude. Also, because most users are ground based 100m may seem adequate as a positioning system accuracy in x and y (lat. and long.). However, when it comes to altitude users seem particularly sensitive to in-accuracy (100m is a lot of altitude inaccuracy when you're landing a 'plane!). It is not at all uncommon to see in-accuracies of over +/- 250m in altitude in consumer and OEM units. This is merely a function of the design of the system, the geometry of the satellites and the quality of your receiver. Altitude does not affect use of your data logger.

[Note: Even with use of differential signals and high grade receivers, altitude is always the "poor brother" compared to lat. and long. by a factor of 2-3.]

Weight : 230g (8oz.)

Total miles & feet or kilometres covered

Count of waypoints recorded and stored as readable file with edittable comments

Moving and dormant trip splines for operator analysis (exception reporting)

Data saved and formatted for analysis by office tools (Lotus123, Excel, etc.)

Time of day versus operator timesheet vehicle use analysis

• Office tool macros allow low cost and flexible format display of route taken and other data