FAQ – Frequently asked questions.

How do I create a heat with more drivers than I have lanes. (Round-robin)

How can the best qualified driver be the first to choose lane.

When track power goes off, I sometimes get communication problems or “unexpected reset”.

My remote control is not working.

LapMaster gets a different COM-port each time I reconnect it to my computer.

Does LapMaster have a log of all laps raced on the track.

How do I connect the LapMaster system.

How do I connect the LapMaster system to a SRT power relay board.

Question: How do I create a heat with more drivers than I have lanes. (Round-robin)


Answer: The trick is found on the driver entry list. In the field “Max drivers per heat” you define the maximum number of drivers that you will allow in a single heat.


Sample: In this sample we have 18 drivers on an 8-lane track. Running with a standard heat distribution you would have to run two heats of 8 and one with only 2 drivers. Alternatively you could run 3 heats of 6 drivers to get a more even heat setup. However the time taken to do it will still be that of 24 stints.

So therefore you might consider running “Round Robin”, which basically means that one or more drivers “sit-out” during the heat that they are running in. You would therefore run two heats with 9 drivers each, and only a total of 18 stints.

To set it up, change “Max drivers per heat” to the maximum you will allow in any heat. (=9)  LapMaster then suggest the heat distribution to be “9 9”. If you want differently, now is the time to change the “Heat Distribution”. When you are happy with the heat distribution, click on the “Assign Heat and Lanes” and you are done. If you examine the setup you will see that the drivers not racing in the first stint, are assigned “Virtual” lane numbers which does not exist on the track, but merely indicates an starting order. In this case “9”.




Question: How can the best qualified driver be the first to choose lane.


Answer:  After qualifying, use the “Assign Heat and Lanes” button to assign drivers into heats as usual. Never mind that they also will be assigned a sequential lane assignment in the same process. Then click on the first drivers “Lane” field. A dialog will now open that allows you to do lane re-assignment. Assign new lanes by clicking on the lane number/color box. Lanes already taken in that heat will be indicated by a strike-out on the button. If you need to redo them. Close the dialog and start over from where you want.


Sample: You started by clicking on the first driver’s lane field (Red arrow), then the re-assign dialog opened up.

Driver #1 then choose to start on “3/Yellow”, and you clicked as indicated by the green arrow. LapMaster assigned “3 (Yellow)” to the driver. (Never mind that currently this is also assigned to another driver. We will correct that later.) As you clicked, LapMaster indicated the selection by striking out the number 3 button (Green arrow).

LapMaster also progressed to the next driver (#2). He choose “5/Black” and as you clicked the “5” button the cycle repeat and will continue until all drivers have made their selection, at which point you exit by pressing “ESC”.



Question: When track power goes off, I sometimes get communication problem or unexpected reset”.



Answer: You are most likely missing what is known as “Lash-back” diodes on your external power relays.

Relay coils generate a magnetic field to operate the relay contacts. When power is removed this magnetic field deteriorates but causes a huge electrical noise spike to be generated. In fact this was how early automobile ignitions systems generated the spark in the sparkplugs. This noise spike is known to cause the LapMaster hardware, the PC or the USB converter chip in the serial-to-USB cable to reset unexpectedly.


The cure is to place a small electrical component called a diode on the relay terminal. The diode only conducts current in one direction. It is mounted to that it will not short-circuit the DC voltage applied to drive the relay, but fortunately the voltage spike created by the release of the relay, has the opposite polarity, so this energy is quickly dispersed by the diode.


This problem is so common, that 8 lash-back diodes are now part of the standard delivery with LapMaster. Just in case you don’t have them already on your power relays.


There are many suitable diodes to choose from. One of the most common, the 1N4001 (a 1 amp diode) is doing the job perfectly.


Sample: The diode most be positioned to that the terminal marked with a silver ring points towards the positive supply (red).


Note: By electrical standards, the red wire is positive, and black is negative.

However observe that for slot-racing, the Parma colors of controller connects have the standard of Red=+ and Black=- reversed!

Beskrivelse: Beskrivelse: Beskrivelse: C:\Users\Carsten\Pictures\IMAG0094.jpg


Question: My remote control is not working.

Answer: Apart from the obvious, that the battery is flat, a problem occurs if you accidentally change one of the white switches under the battery flap. Especially when closing the battery flap, there is a change that one of the small switches gets pushed out of the correct setting.

By default the switch setting should be OFF-OFF-ON-OFF-OFF. This must match the setting in the LapMaster hardware box. Now if you have multiple LapMaster systems in the same building, it is possible to choose a different setting for the LapMaster hardware and its remote. However they must always be identical, in order for the remote to control the track.

This is a radio frequency remote. The remote will work for up to 30 meters in free air. However concrete walls or other obstacles in the path between the LapMaster hardware and the remote (including your body) might serious degrade the range.

Note 1: LapMaster refuses trackcall in the final seconds of a stint. However if the trackcall was called from the remote, it is possible that the remote control is now in the wrong position, meaning that you might need to press “On” before you can turn it “Off” again.

Note 2: The battery is a 12 Volt battery (A23S). 3 volt batteries of the same physical size exist. When replacing, make sure you replace it with a 12 volt battery.

Beskrivelse: Beskrivelse: W:\Carstens\LapMasterExtra\DSC02255.JPG


Question: LapMaster gets a different COM-port each time I reconnect it to my computer.

Answer: If you connect your USB plug to a different USB connector on your computer than that from last time, the Windows USB driver will assign a new COM port to it. When reconnecting, make sure you use the same USB connector.

Also if you have done this a significant number of times, eventually you will get out of the max COM number supported by LapMaster. You then need to reset the com port numbering.

Sample: From Windows Device manager, Identify and click on the Serial-to-USB converter. (Cable must be attached). Select “Advanced”. Then at the bottom you can assign any Com port you like to this device.


Question: Does LapMaster have a log of all laps raced on the track.

Answer:  Yes, LapMaster keep a log file on each and every lap ever raced on your track.

1)      On the main page, click on the "Result" button.

2)      Then from that panel click on the "History" button.

3)      Then select the file in "C:\LapMaster\History". There is a file for each day you have had started the LapMaster program. The files are names "History" + 2 digit year + month + day + ".txt". Double click on a file, or select it and click on the “Open” button

4)      A LapMaster display  panel opens that allows you to view a formatted display of all laps from the day in question.



Note:  If you do not close LapMaster , and time passes midnight, the data is still recorded in the original file. LapMaster does not create a new file (with a new date in the name) unless you close the LapMaster program in between.


However the files are also "Tab separated" text files, which means that you can view them in an editor like Notepad, or load it directly into a spreadsheet like Excel.

The fields in the file (in sequence) is:




The date that the log entry was created in the format (yyyymmdd).


The time that the log entry was reorded in the format (hhmmss.millisec).

 Note: This is not the same as the time the car was detected on the deadstrip. It cannot be used for determining lap times.


0 indicates this line is a counting event.
1 indicates this line is a message.


Name of driver.


Heat number when racing heat race.


Stint number when racing heat race.


The lane number. (As a number, color is not used in the log).


The lap count in the stint.


The total lap count.


A 0 indicates a non-clean lap. That is power was interrupted during the lap. The time cannot be used as a lap time.

A 1 indicates a clean and valid lap. The time can be used.


Round number of race. (When running multiple rounds races.)


All races are automatically counted and assigned a number. This raceID or Race-number ties all events together that are part of a valid race.


Loading the History file into the spreadsheet opens up all kind of statistical possibilities. Also you might be able to find answer to a lot of questions asked after the race.


Question: How do I connect the LapMaster system.

Answer:  You might also have a look at this diagram:


If you are confused by the diagram, here is a more practical verbal guide on how to connect a LapMaster system.


Domestic Power:
The supplied power packs are universal and will run equally well on 220/110 Volt, 50/60 Hz.
All you need to do is to attach a power plug of local type to the supplied extension cord.


The package includes a wire harness made up of Computer LAN cables. One cable has been cut and the wiring exposed.
Each pair of wiring has a solid colored and a white/Striped wire. The solid color wire has been marked
with lane number and “Right”, and needs to go to the right side of the deadstrip as seen from the driver’s position in the cars.
The striped wire needs to go to the left side deadstrip.
The LAN cables connect with connector blocks to the LAN type wires coming out of the LapMaster unit.

These has been labeled Lane 1-4 and 5-8.
An extra set of connector blocks has been supplied for our convenience, so that you might extend the cabling with easily obtainable
LAN cables to any length that you want.


Track power:
LapMaster is supplied with a block of 9 screw terminals. One wire in a separate color is the common wire.
Then follows the lane-1 to lane-8. You need this wiring to drive external track power relays.

If you already have a SRT power relay connection board, see this How do I connect the LapMaster system to a SRT power relay board.


It is absolutely mandatory that your relay coils are equipped with what is known as backlash-diodes.
The SRT board has this already. If you do not already have these diodes in place, diodes are supplied in the
LapMaster delivery for your convenience. They are small black things with 2 wire ends, and a marking with a silver
ring at one of the wires. The diodes must be placed across the relay coil terminals in such a way that the
silver ring point towards the positive power supply.

See also: When track power goes off, I sometimes get communication problems or “unexpected reset”


Your Computer needs to run Windows XP, Vista or Win/7. It is expected to run on Win/8 as well but that has
yet to be verified.

If your computer has a serial port (RS232) connect LapMaster to this.


If your Computer dosn't have a serial port, use the supplied USB-to-Serial converter cable. When you attach the cable the first time, the Computer
might or might not ask for you to insert the LapMaster CD to install the device driver for the USB cable.


If you need to lengthen the distance from the computer to the LapMaster box, extend the serial cable. You should not extend the USB cable.


Insert the CD in the Computer and double click on the LapMasterSetup file on the CD.

After installation, you must associate the LapMaster program with the LapMaster hardware.

To do that, start the LapMaster program. Accept the "Demo" mode the first time you start LapMaster.
Then click on "Setup"->"Program Setup" and click “Search” to ask the program to search for the COM port that the LapMaster device is attached to.

(LapMaster must be connected and powered). Click "OK" to save the connection. LapMaster will close.


Start LapMaster the second time. Now click on "Setup"->"Track Setup", and customize LapMaster to suit your track.

(Number of lanes, lane colors, length, name etc.) Click on "OK" to complete. LapMaster will close.

You can now restart LapMaster for the 3'rd time, and you are now ready to race.
Don't forget to use the "Help" key. It will guide you through every step of the way.


To connect LapMaster to your web page with LiveTiming, click on "Setup"->"WEB setup".
The WEB setup is aided by a setup wizard, however you need to know a few basic things like FTP
userid and password to your website, in order to do this. If you intent to integrate with UStream webcast,
you need some connection information (Embed) that you get from UStream.  


Question: How do I connect the LapMaster system to a SRT power relay board.

Answer:  If you have an existing SRT relay board hooked up, connection of LapMaster could not be any easier.

The SRT relay board looks like this:

This is a closeup of the relevant connections:

The LapMaster box comes with relay connections wired to a screw terminal connector block:

8 of the screw terminals are in the same color, and marked 1 to 8. They need to go to the 8 terminals marked with a white block on the SRT board. (Lane-1 is on the left.)
The 9’th terminal in the LapMaster connector is marked “C” for common, and needs to go to the terminal on the SRT marked with a black box (Negative).

That’s it, for the power connection. See How do I connect the LapMaster system. For the remaining aspects.