Initial installation

(This section of the help file will automatically be displayed the first time you start the LapMaster program.)

Software install

The LapMaster program must be installed on a Windows based computer (Win-XP, Vista, Win/7,Win-8.x or Win-10).


Serial-to-USB cable:

Actual it is not just a cable, but an USB device is hidden inside the cable.

However with current day Windows, the required driver are already available within Windows.


Note on Upgrade:

If you are doing an upgrade, you should always remove the previous version first. You do this using the standard Windows “Control panel” and “Remove program”.
This will retain your custom settings and data, so that they can be reused with the upgraded program.

To reinstall completely from scratch, without retaining any of your settings, history files, race results or any other customizing you might have done, then also delete the “C:\LapMaster” directory before reinstalling.



To install the software, simply click on the “LapMasterSetup3.xx” program on the LapMaster install CD or supplied USB stick.
Alternatively download the latest version from

A shortcut to the LapMaster program is automatically placed on the “Desktop” and in the “All Programs” list.


The next step is to connect your hardware (see below), and then customize your settings for LapMaster so that it will suit your needs the best.

During the customization process, LapMaster creates a “c:\LapMaster\LapMaster.ini” file that contains all your individual settings.



LapMaster also maintains its list of lap records in “C:\LapMaster\LapMasterRecords.ini”. You can edit or delete this file if you want to correct track records after the fact.

All of your racing history is logged to “C:\LapMaster\History” You might want to clear or archive the history maybe once a year.

If you use the “Publish to WEB” facilities to automatically publish race results, then a copy is also maintained on your harddisk in “C:\LapMaster\Results”. You might want to prune that over time as well. To totally reset the result index on the internet, delete the file “C:\LapMaster\Results\LapMasterResultLink”, and the next time you upload a result, it will start on a fresh new index list.

Initial program setup

Before you use the LapMaster program for the first time, you must set it up to match you race track. This is done in two parts, first the program setup and then the track setup.

Program setup:

1.      Start the program, I.E. by double clicking on the LapMaster shortcut. When it loads, you will start in the Main display

2.      First select the Race Setup button to enter the race setup menu.

3.      Then select the Program Setup button to enter the program setup.

4.      Select the COM port that you have connected the LapTimer-II device to or simple press “Search” to let the program find the COM port.
The “Search” assumes that you have a connected a LapMaster device and that it are powered on. Otherwise it will not be able to find it.
If you already know on which COM port you connected the LapMaster unit, you can set it manually.
If you manually select “(None)” you will be able to run LapMaster in simulation mode without the hardware.
(Note: Connecting the USB cable to a different USB port on your computer is most likely going to assign a new COM port the device.)

5.      Next you should select the language you want. Press the “Change” button, open the directory appropriate directory, and then select the “Dictionary” file.

6.      If you change either the COM port or the Language, the program will issue a message that it will restart. Just press ok and reload the program again.


Track setup:

After a program restart you will again find yourself in the main display.

1.      You must again enter the  Race Setup

2.      Select the Track Setup button to enter the track setup.

3.      Fill out the information about you track, the length, the colour and rotation scheme etc.
Use the “Help” if you need guidance on any of the track setup information.


You are now ready to use the program. See the section “Running a race” on how to use the program.


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The LapMaster program uses the service of the LapMaster hardware. This comes in a 4-lane and an 8-lane version.
Inside the unit are 1 or 2 computer boards (4- or 8–lanes) and also a small radio receiver for the wireless remote control unit.


Computer connection:

The LapMaster hardware has a RS-232 (Serial) port. This can connect directly to a computer that has a serial port. However this has become rare. Modern computers use the much more versatile USB ports. To connect to an USB port, you need to use a Serial-to-USB converter. One has been supplied with the hardware.



A dead-strip is a small section of track (~20 cm) with the electric power rails isolated from the rest of the track. This part of the track carries no power and the cars can only “roll” over it, thus the term dead-strip. You should make the isolation between the power rails long enough that the guide braid cannot make contact on both the power rails and the dead-strip at the same time.

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The dead-strip is connected using the kind of multi-wire cables also used as computer LAN cables. Each has 4 pair of wires. Each pair consists of a solid colour and a white with a stripe in the same colour as the solid. The pair has been clearly marked as to what lane, and also the solid colour cable must go to the right side of the track. (As seen from above in driving direction. This is also known as the plus side of the power). It is very important that the polarity is correct. The dead-strip is powered to make sure we can count even if the car stops on the counter. However when the car crosses at speed, it act like a generator and actual supplies voltage to the dead-strip. When connected correctly this voltage adds to the bias voltage, make it easier to count. If the dead-strip wires are reversed it will counteract, making it harder to count.
P.S: This assumes that you use the international standard of “plus-to-the-right” for the track wiring. If that is not the case, the dead-strip wires must also be reversed.


The LapMaster delivery includes 2 or 4 LAN-cable connector blocks. This allows you to extend the length of the wires from the LapMaster box to your dead-strip very easy with standard computer LAN-cables. These cables are cheap, easy to get hold of and comes in virtual any length.

The dead-strip will not function if your track is wired for reverse driving unless you reverse the dead-strip wires as well.


Note: If you use a voltmeter to measure the bias voltage on the dead-strip, you should find between 3-6 Volts with plus to the left. Maybe this will seem strange to you, but think on a 2 battery flashlight. To add voltage you need to have plus on one battery touch minus of the other. If you reverse one battery, the flashlight will not work.



To use infra-red sensors with LapMaster, you need an external detector/amplifier.

For a description on the IR-sensor system, see IR sensor for LapMaster.pdf

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Powering the LapMaster unit:

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The LapMaster unit comes with 2 universal wall-plug type power supplies.
One supply 12 Volt to the computer boards, the other 5 V for the deadstrip.

The universal power supply runs equally well on 110 or 240 Volt, 50 or 60 Hz.


Track power:

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LapMaster comes with 8 or 4 output power relays. You can wire LapMaster to control everything from just the #1 relay, or you can use 1 relay per lane (Default).

1 relay per lane is preferred, as it allows LapMaster to control each lane individually. E.g. if no driver is assigned to a lane, then there will be no power on the lane either.

If you decide to go with a single relay only, you need to configure this in the Track Setup


External relays and lash back relays:




The relays on the LapMaster board have a maximum rating of 15 Amp.

This is usual not enough for a commercial grade racetrack. In that case you must provide external high power relays.


Existing tracks have these already, otherwise it is recommended to use automobile 75 Amp/12 volt relays similar to these.


When you use external relays it is very important that you fit them with lash back diodes.

The relays work using an electric coil. When power is applied to the coil, it becomes magnetic and attracts the set of contacts. However when the current is removed the magnetic energy in the coil is again converted back into a voltage spike. If this voltage has nowhere else to go, it will travel backwards in your electrical system searching for a way to discharge. This voltage spike can be very damaging to anything electronic, like computers and LapMaster boards. To solve this problem you should fit the external relays with a lash back diode.

A diode only conducts current in one direction. It therefore has one end marked with a ring around it. For this application you need to have the marked end point toward the positive relay supply when the relay is engaged. Then when power is removed the spike will be of opposite polarity, and is quickly dissipated through the diode before it can do any damage.


Many types of diodes can be used. The most common is a 50 Volt/1Amp type called 1N4001. Usual your LapMaster package includes a set of suitable diodes for your convenience.



At any rate it is definitely recommended to use fuses. A 10 Amp would be suitable for all but the most power hungry cars like Opens or Eurosport, where you might go for 20 or 40 Amp.

Power like this is no joking matter. Use fuses or risk fire or damage to track/wiring/LapMaster/Controllers or your power supply.

When a short circuit happens (and they will, e.g. when someone hooks the controller up wrong), then something has to give. It better be a 25 cent fuse than your 500 USD controller or LapMaster or worse. And even if your power supplies say’s 12 Volt @5 Amp, this doesn’t prevent it from supplying a much higher current. It just won’t be at 12 Volt, but it could still easily burn a 10 Amp fuse.


This wiring diagram might help you hook up all the wires correctly:


Note that the middle screw terminal is the common wire.

When the relay is unpowered it is connected to the right screw terminal, and when the relay is powered it is connected to the left.

You would normally use the left and the middle screw terminal.

However if you want your system so that it has power when the computer and LapMaster is off, then use middle and right terminal.

You will then need to go into Track Setup and set the “Reverse relay connection” for the system to function.


P.S: Do not use excessive force when tightening the screw terminals. Excessive force has been known to break the screw terminals connection to the printed circuit board.