Delay between DS race end and PC Lap Counter race end

Guy:

I'm using a DS300 lap counter for detection of laps, and using the parallel port for power control. When my timed race ends, there is a difference of about 8 seconds between when the DS300 times out and when PC Lap Counter times out, so the cars continue to race for that 8 seconds, and if a car passes under the DS Light Bridge, its lap doesn't count.

My computer is running Windows XP. Can you think of a reason why there is this much of a difference in timing between the DS and PCLC? I thought it might be because PCLC has a countdown before the start of the race, and the DS300 starts immediately; would that explain the difference? And if so, how do I avoid the discrepancy? Do I omit the start light countdown?

The difference come from the countdown of Pc Lap Counter, regarding your explanation it's like you let the DS lap counter manage the race, it's better to set your DS lap counter to make 9999 laps and let Pc Lap Counter manage the race.

If I start the race through PCLC, will that also start the DS300? Or do you mean set the DS for a lap-delimited race rather than a time-delimited race and start it that way? Then PCLC will stop the race when its time has run out, and the DS will have counted the laps completed up until that time?

stumbley wrote:

If I start the race through PCLC, will that also start the DS300?

No because the DS300 can't receive command from the computer.

stumbley wrote:

Or do you mean set the DS for a lap-delimited race rather than a time-delimited race and start it that way? Then PCLC will stop the race when its time has run out, and the DS will have counted the laps completed up until that time?

Yes that's what i mean, set the DS to make 9999 laps so the DS300 will never stop counting laps and let Pc Lap Counter manage the race.

Thanks, Guy. Tried it and it works fine.