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timing: labview time seems to come in bursts

I'm trying to sample some voltage signals at around 100-1000 Hz (using a PCI-6229) and simultaneously correlate these samples against an absolute time.

 

So, for example:

 

0.001 s, +1.0 V

0.002 s, +1.1 V

0.003 s, +1.2 V

0.004 s, +1.3 V

0.005 s, +1.4 V

...etc

 

However, when using the "Get Date/Time in Seconds" function in LabView, the timing comes in "bursts" like this:

 

0.047 s

0.063 s

0.063 s

0.062 s

0.078 s

0.078 s

0.078 s

0.078 s

0.094 s

0.094 s 

 

This is regardless of whether I use the aforementioned function or if I read the data as a 1D Waveform and pull out the t0 values.  

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Hmmm, never mind, got around the problem by switching to the "Tick Count (ms)" function.

 

But just out of curiosity, if someone could explain why the "Get Date/Time in Seconds" function behaves like that I'd appreciate it.

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That time comes from the Windows clock which has a resolution of only about 16 msec.
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