How do I built a frequency vs. time graph from voltage analog signal (in labView or signalExpress)?

[Netta]

Hi,

I'm interested in listen to and record dolphins in the water. For that I need frequency vs. time graph. So far I only got frequency in the x axis, never the y axis.

I cannot change the analog signal from voltage to frequency (my device PCI-6132 does not support it). The measurements will have to come from voltage.

If someone knows how, and can help, I will be grateful.

Thank you,

Netta

[Jake_H]

It looks like you're going to have to use a Fourier transform within the VI to convert your signals to frequency. Check out the links below to get you started.

FAQ

http://www.ni.com/support/labview/toolkits/analysis/analy3.htm

Tutorial

http://zone.ni.com/devzone/cda/tut/p/id/4541

[weak.element]

first you have to take the fft of the signal you want to analyze and then you use the intensity chart or intensity graph which ever suites you best to get the required graph. The frequency will be on y-axis and the time will be on x-axis.

the simple VI is attached for the help.

my problem is other way around i want the frequency to be on x-axis and time on y-axis if you can help me in this regard.

thanks