how can I create a command based on peak values on a waveform chart of a frequency response?

[chaim]

The background is that we are using a microphone to capture the sound of a
coin hitting a bell.  We are able to use LabView to capture the analog
voltage signal and display the FFT of the signal in a waveform.  The
trouble we are having is figuring the proper coding or vi to use to
capture the peak frequency (that is almost instantaneous) so that we can
actuate another command based on a peak value that has passed through the
waveform.  Basically, each drop of a coin must be paired with a distinct
value.  The waveform is capturing it just fine, but how do you extract it
and trigger another command based on this value?

Howard

[Jennifer O]

Hello Howard,

There is a signal processing function "Extract Single Tone Information" which will take in a waveform and return the frequency, amplitude and phase of the tone with the highest amplitude.  You can compare the results of this function with a particular threshold or value and use a case structure to execute one or more different actions based upon the comparison.

Hope this helps,

Jennifer O.
Applications Engineer
National Instruments