Showing results for 
Search instead for 
Did you mean: 

Frecuency counter for digital square wave

Hi All:


I am new in LabView 2012.


I would apreciate very much if someone can help me with this:

I need to measure the frecuency change of a square digital signal coming from an IC sensor that change the frecuency of this signal when you change light intensity.


A frecuency counter is perfect for this.


The max  frecuency is 120 KHz ( max intensity)  and 5 Volts max , 0 volts min. But of course this frecuency will change according to light intensity to smaller values.


I have built in the past a data acquisition systems with labview, but never a frecuency counter.

Does lab view has any frecuency counter function?

Do you know if someone has a an example so I can see how this frecuency counter was built.

If someone can help me with this I wouyld be very thankful


best regard


Cristian Cox

0 Kudos
Message 1 of 4

Cristian Cox,


It depends on which DAQ device you are using. Many of them have counters which can be used to measure frequency.


If your device has hardware timed digital inputs (many do not), you can use that.


If your device has hardware-timed analog inputs (most do), you can use Extract Single Tone to get the frequency.



0 Kudos
Message 2 of 4

Lynn, thanks very much, I will check this information.


I will borrow this DAQ next week but as I understand, this is a 

NI USB-6000




  • 8 analog inputs, 10 kS/s; 12-bit resolution
  • 4 digital I/O lines; 1 32-bit counter
  • Lightweight and bus powered for easy portability
  • Easily connect sensors and signals with screw-terminal connectivity
  • OEM version available
  • Compatible with LabVIEW, LabWindows™/CVI, and Measurement Studio for Visual Studio .NET
0 Kudos
Message 3 of 4
The USB-6000 only does edge counting as you can see from the specs. The counter input cannot measure frequency so you'll have to use the analog input as mentioned above.
0 Kudos
Message 4 of 4