Wrong pulse counting for tick based pulse generation for USB6210

I try to generate 50 HZ pulse in USB 6210 with sample code "http://zone.ni.com/devzone/cda/epd/p/id/3088". But doesn't work properly.
Please see attachment:
app.jpg: pluses setting. I set 200000 ticks to low and high.
Tick count based.jpg : result wave from oscilloscope.
You will see low is 3 times longer than and high.
Do you have any idea?
Thanks.
Attachments:
app.JPG ‏35 KB
tick count based.jpg ‏2431 KB

[email protected],
Does this happen on ctr0 as well? Also, have you tried decreasing the low and high ticks to something more like 1000? I'd like to see if we can get the output to look as we expect. My last question is, what are you using for a trigger source? Have you tried this with a non-retriggerable example? If so, does it output the same incorrect waveform? Thanks for the pictures. Those are always helpful for visualizing the situation.
Robert B
Applications Engineer
National Instruments

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Block Diagram
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Wrong pulse counting for tick based pulse generation for USB6210

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