LabView - Timing Measurements from AD Data

Hi!

Well, first I need to know exactly what you mean: is AD "analog device", "analog data" or "acquisition device" or something else? And you need to measure when the signal starts and when it ends?

If that is the case, there are two nodes you could use: "Tick Count.vi" or "Timestamp.vi". Now if you need to convert that time sequence in seconds, I recommend the second.

For example, you could have a while loop where you monitor the current value from your input, and test there if the signal started, maybe with a case structure. When it starts, call Timestamp.vi and end the while loop (use a True constant for the "Stop if True" button). Then start a new loop where you check when the signal ends. When that happens, call Timestamp.vi again and end the second loop. The only thing left is to calculate the difference between the outputs of the two Timestamp vis.

To achieve accurate dataflow, you need to make sure the second while loop doesn't execute in the same time as the first one, so use a wire to connect them (say the DAQ Task for example).

If you haven't used LabVIEW that much or if what I said sounds too complicated you can either go to Help and Find Examples (I don't have the software on my computer now so I can't help you with that) or sign in on the www.ni.com website - their web support is excellent.

Good luck with your measurements!

Patricia

P.S.: I had a summer job as tech.support eng. at NI ;)

A 60Hz AC relay with a set of contacts connected to timing devices? Does it need to be more complicated than that?