how to get frequency of input analog voltagesin sin wave

[eeyc]

hello !!
i have small question about frequency of square wave
i have 2 ADQ card,and labview 7.1 software.

i create ADQ assistant object and that cheking me 4 port of anlog input (5000HZ with 1000 semple read) and connected to graph scop,
one of this analog input get from another system square wave (10V OR 0V),
now i try to know frequency of this wave.

if there any way to get this frequency parameter i will happy to know

thank's of any response.
eyal

[Ima U]

Hi eyal,

From my understanding, you are using the DAQ Assistant in LabVIEW 7.1 to take in an analog square wave.  You would now like to get the frequency of this periodic signal.  You could use the Spectral express VI.  When you right click on the block diagram and look under Express>>Signal Analysis, you can select Spectral.  This express VI will calculate the FFT of a signal that is input into it.

I hope this helps!