You can use this software when you want to time the race laps.
BS Editor: Kart Tracker provides the ride or race organizer the ability to keep track of and display the leaders and lap times of an event. It works in conjunction with the AMB Timing systems hardware and transponders (not included).

In its basic mode, Kart Tracker will not only time the race laps and constantly update the display of the race order, but also control any lights or power supplies at key points of a race. It also keeps a database of track activity for scheduling maintenance or monitoring ridership

Where things get really exciting is Baxel has partnered with Xtreme Racing and Greg Ballard (see image below) to provide a total multi-media experience to the racer. In an arcade setting, Kart Tracker will play background music, show videos before and after a race, and announce the race automatically. You may record your own sounds and videos, or lease a complete race-tuned set from Greg. Its exciting to watch and frees up at least one attendant. Contact Xtreme Racing directly for availability and price for this add-on.

Feaures to look for are:
Configuration of communications
Setting of cusco racing duration in seconds or laps
Colors for the display
Mapping transponder numbers to Car numbers
Power control
Announcement timing
Volume levels you can free download Kart Tracker 1.6.6 now.