Clock specs for USB-6009

[avergara]

Hello,

  I tried to look for timing specs for the USB-6009 multifunction DAQ but could not find any.  We would like to compare two acquisition systems over a long period of time (several hours).  Previously I have noticed what looks like a drift in sample timing over a long period (a few samples over an hour at 100 Hz) between a USB-6009 and the the system.  I don't know if its an error of either or both.  Are there specs for expected drift in the sample clock over time as compared to a universal standard like an atomic clock or the like?

Thanks

-Alex

[JÞB]

see the thread " system clock used to update"

 you state;

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"Previously I have noticed what looks like a drift in sample timing over a long period (a few samples over an hour at 100 Hz) between a USB-6009 and the the system."

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I'm assuming you mean "the uncalibrated system clock seams to be inconsistant with the calibrated timer in the USB 6009."  Ignore the system clock it is not comparable to the SI Second.  The timer on the 6009 is, its drift can be found in the NI specifications, its error can be determined by a calibration facility.

Good Luck