Delayed and Gated Pulse Train

[klynch]

I am trying to use Labview as a control for a pulse-burst laser system, but am having problems syncing various signals. The laser is amplified with flashlamps, which fire at 5 Hz. The flashlamp power supply is outputting a 5 Hz signal to be used to trigger whatever is needed. I'm trying to do multiple things off of this signal, but am facing problems:

> Create a burst of 68 small (30 ns) pulses within a firing window
> Delay this firing window to an optimum time within the flash
> Hold off triggering for a small amount of time to prevent noise from delivering multiple triggers (the power supply output is not very well conditioned)

Im currently running two counters on a NI-6602 TIO card, Labview 8.2, one as a continuous pulse train with a 30 ns high time and a 8 us low time. I am then gating this, with a gate triggered by the power supply output. However, when I do this, the continuous pulses "jitter" within the gate window. If possible, I'd like them to stay synchronized with the gate and trigger. Also, is there a way to do a trigger holdoff with this? I tried using a digital filter but that introduces more jitter.

Any help would be greatly appreciated! Thanks!!!

[DJDDA]

If I remember correctly, you can't programmatically handle events in the nanosecond range. I think microseconds were also a problem; apparently modern computers aren't able to accurately handle events with a width of a lower order of magnitude than milliseconds.

[jaced]

Hi,

I would like more clarification on what exactly is happening when the jitter occurs.  Is it uniformly out synch, meaning is each pulse off by a common amount. Or does it vary from pulse to pulse? Also it is a little confusing as to exactly how the system is configured. As I understand it you are using the power supply trigger to both start your output and trigger some external circuitry that inputs a constant high into the gate of the NI-6602 until I assume another trigger is received. If I am incorrect in the set-up please correct me.  Perhaps a screen shot of your code would clarify things.

[klynch]

Thanks for the help guys, but I figured out what the problem was. Before, a continuous pulse train was running in the background, and was gated at the correct time. However, this pulse train was not properly triggered, and the jitter was caused by the pulse train being out of sync with the incoming trigger signals. Using two counter signals, Im now able to holdoff a trigger for a specified period of time and delay the pulses.

Thanks again for the help though, I appreciate it.