Frquency & Duty cycle Value changes- every time

[Sumithra_Nagappan]

Hello all

 im using pcie 6320 to measure the frequency and the duty cycle of a signal.i have attached my vi & the data measured for reference.The values highlighted in red ,is my actual frequency and duty cycle but values changes for every 1 sec.Please correct me if i have any mistake.

[John_P1]

You'll need to enable digital filtering--insert the following property node into your code (call the property node before starting the task):

Try a "Min Pulse Width" of a few us and increase it if you still are picking up incorrect readings.

The errant numbers are coming from false edges being picked up during transitions, enabling digital filtering will cause the DAQ device to ignore any transitions with a pulse width of less than the set value.  Your 475 Hz 72% duty cycle signal should have a high time of about 1.52 ms and a low time of about .59 ms):

656 Hz = ~1/(high time)

1718 Hz = ~1/(low time)

MHz values = multiple edges picked up during a single transition.

Best Regards,

[Sumithra_Nagappan]

hi..

i tried as you said,but im getting the following error.

[John_P1 · Accepted solution]

You need to set CI.Pulse.Freq.DigFltr.Enable and CI.Pulse.Freq.DigFltr.MinPulseWidth.  

You have selected CI.Freq.DigFltr.Enable CI.Freq.DigFltr.MinPulseWidth.

These are two different types of counter input task (though they are unfortunately named very similarly to each other).

Best Regards,

[Sumithra_Nagappan]

Thank you Mr.John.Now im able to measure exactly.