I’m assuming your final application will be measuring a
signal with DAQ hardware and the switch it just a way to test your algorithm. If
you have an E or M series DAQ card I recommend using one of the onboard
counters to measure the high or low pulse width for you. A great example of how
to do this can be found in the NI Example Finder. In LabVIEW go to Help
>> Find Examples… >> Hardware Input and Output >> DAQmx
>> Counter Measurments >> Period or Pulse Width >> Meas Pulse
Width-Buffered-Cont.vi. You can change whether it measures the high time or low
time based on how you set the starting edge input on the create channel vi.
Falling sets it to measure the low time and Rising will make it measure the
high time. You can then manipulate the
data returned by the DAQmx read to only display the latest four results. Please
let me know if you have any questions and take care.
Thank you for answering to my message. You are right, my application is measuring the pulse width of a signal. The thing is: I have to use the PCI-DIO-96 board. That is why I have to use software to measure it. I know that with a board which has a counter, the job is much easier but I don't have that kind of board :(.
Here is a VI I wrote that I think does what you are looking
for. It is only going to be accurate down to at most 1 ms, and due to Windows
not being deterministic, it probably will not be even that accurate. Let me
know what you think and if this helps. Have a great week.
