How to properly align Derby Timer track sensors

The most common support issue for Derby Timer customers is not having under track sensors aligned so that the top display can see the under track sensors.

READ ME FIRST - Understand The Display Indicators

The decimal point in the bottom most digit (lane number digit) indicates if and when the display cannot see the sensor.



A lit decimal point indicates a "broken beam".  

In normal operation, you would only see the decimal point light up when a car is blocking the beam.  If the decimal point is lit (or flashes) when there is nothing blocking the beam, the timer will not operate properly.

Step 1 - Align Under Track Sensors

The sensors need to be aligned through actual testing.  The position of the overhead display and under track sensors should be adjusted through trial and error, so that no decimal points are lit on the bottom lane number digit, unless something (like a car or your hand) goes between the track and the overhead display.

Once there are no decimals lit on the lane number digit, and you don't see any slight flashes, the display unit SEEMS TO BE aligned properly with the under track sensors.  You should always verify sensor alignment, as described in the next step.

Step 2 - Verify Sensor Alignment

Sensors are checked at least 2000 times per second.  Slight misalignment can cause a very small error rate, and a very small error rate will produce false finish triggering.

Drop the starting gate (or move the gate sensors apart) to "start" a race.  The green light should start flashing, to indicate a race is in progress.  Let the race run for at least a minute without blocking an lane sensors.  If the large top digit displays a digit, indicating it thinks a "ghost" car passed through, that lane sensor position, or the display position, needs to be adjusted.

Do not consider running an event until all your lanes will consistently run test races of at least a minute long, without triggering "ghost finishes".

Note - What if the lane number digit shows "-"?

A dash for a lane number indicates the timer went into "ready to race" mode, without being able to see that lane sensor.  Since it could not see the sensor, it disabled the lane.  Ignore this until sensors are aligned, using the above procedure.  Once aligned, the lanes should report their lane number when the gate goes up.