Timing issue with 'Elapsed Time' VI

[kyle123]

I am very new to LabView and am having troubles understanding the Elapsed Time VI. I am connecting the Elapsed Time VI in the block diagram to a numeric indicator all inside a while loop. I am also tabulating the results from each iteration with an express table. I set a 'Wait until next ms multiple' VI in the block diagram with a '50' as its input. I was expecting to see a column containing multiples of 50ms however it appears to be inconsistant ( some iterations are 62.5ms and some are 46.9ms). Is there a way to improve the timing of each iteration?

[Robert Wiggenhorn]

Kyle,
    The elapsed time express vi does not provide accurate resolution in the ms.  However, there are other alternatives that will allow you to show the timing of your while loops with ms resolution. I have included an example of a vi that illustrates one possible solution to your problem. The example included subtracts the value of tick counts to calculate how long the loop has been running. Hope this helps!



Robert W.
Applications Engineering
National Instruments