measuring the frequency using PCI 6221 Daq card

[thinnker]

Hi

I want to find the frequency of an external signal.

How can i do that give me some idea or example.

Regards,

Hari

[Henrik_Volkers]

Two usual ways:

Use the counter input. (good for clean signals, keeps the analog inputs free, doesn't need lot's of computation)

Got to Help / Find examples ... / Hardware Input and Output / Counter Measurements/ Digital Frequency /

Use the analog input and use signalprocessing vis to extract the tone frequency and phase

How does your signal look like?(sine,square, amplitude, offset, noise, ?? )

Frequency range?

Needed resolution?

[thinnker]

Hi Henrik

I tried that example its working fine, but i need to diaplay that singnal in graph.

And one more is how can i start(Trigger) the measurement(frequency measurement).

Regards,

Hari

[Henrik_Volkers]

If you need to capture the waveform look at the aquire waveform examples and add the

Extract Single Tone Information VI

Owning Palette: Waveform Measurements VIs

Requires: Full Development System

Takes a signal in, finds the single tone with the highest amplitude or searches a specified frequency range, and returns the single tone frequency, amplitude, and phase. The input signal can be real or complex and single-channel or multichannel. Wire data to the time signal in input to determine the polymorphic instance to use or manually select the instance.

(copied from the help)