How does WDT's 't0' synchronize with computers clock?

[RLD]

When reading a MIO-16E DAQ card with the Waveform Data Type the t0 value returned is local date and sample time resolved to fractions of second. How is this value sychronized to the system time? How closely will date/time stamps generated by other 3rd party app's match DAQ time for common events?

[Darren]

Hello,

To my knowledge, the "t0" value is obtained whenever the AI Start function (possibly the AI Read...I'm not entirely sure) is called in your block diagram. At this point, the function simply queries the system clock and brings back that value as the t0 value. I believe that queries to the system clock, regardless of programming environment, have an accuracy on the order of 10s of milliseconds. Thus, if you have other 3rd party applications making system clock queries, you should find that the times given in all your software applications should be very close to the same (on the order of 10s of milliseconds).

I hope this sheds some light on your question. Good luck with your application, and have a pleasant day.

Sincerely,

Darren Nattinger
Applications E
ngineer
National Instruments