Waterfall display

[Sonti_11532]

Hi,

I'm displaying the sample on spectrum (Waveform graph). Parallelly I want to display the same samples in "Waterfall" spectrum.

Please find the enclosed VI and help me for Waterfall plot.

Regards,

S Nagaraju.

[Bob_Schor]

You need to explain a little more what you intend.  Your example shows one set of data being plotted over and over again -- this makes no sense.  I think I may know what you want, and can make some suggestions, but you need to provide more information and, perhaps, an example of what you want the final output to resemble.  Be sure to include the origin and acquisition of the data being plotted.

Bob Schor

[Sonti_11532]

Hello Bob Schor,

Actually I'm getting the samples from ADC board via Ethernet over Tcp/ip link. I need to perform the FFT for the samples and display the spectrum (frequency Vs amplitude). Upto this I'm able to do. But, as per user requirements I want to show the same output data in waterfall display like real-time spectrum. 

One set of samples I captured and and attached in that array. 

Kindly help me. 

Regards, 

S Nagaraju. 

[Bob_Schor]

Do a little more work yourself.  You've shown code to acquire one sample and plot it, but there's nothing in the code about multiple samples (how many?  how often?) nor an example of the plot you are trying to make.  [I think I know what you want, but you are the one with the "user requirements" and presumably understand what you mean by "waterfall display like real-time spectrum".  If you can't describe it in words, or show a picture of it, then you can't program it, and should go back to the User and tell him/her this.]

Here is a hint that may help you in your thinking about what I am asking -- are you talking about a plot/graph?  How many axes does it have?  What are the axes (what data-specific variables do they represent)?

Bob Schor

[Sonti_11532]

Hello Bob Schor,

Actually the example code which was shared is a part of my main application. For demo purpose i have taken one set of samples and presented on the waveform graph continuously. Every time I'll get 20K samples for every 1 Sec. 

I'm talking about FFT output waveform graph with two axis Frequency and Amplitude.

The example screen is attached here.

Please help me.

Regards,

S Nagaraju.

[wiebe@CARYA]

Looks to me like you want a spectrogram.

Give "STFT Spectrogram PtByPt.vi" a try (use quick drop)...

[Sonti_11532]

I tried the same, but not able to plot properly.

Please find the enclosed VI.

Additional Info: Total 20480 samples, Fs=5000MHz, Measure Frequency = 1000MHz.

Kindly help me.

Regards,

S Nagaraju.

[wiebe@CARYA]

Set the intensity graph z-scale to autoscale.

[Sonti_11532]

I made z-scale to auto scale, but there no much difference.

[wiebe@CARYA]

I don't have your DAQ system. I replaced it with a generated sine waveform, and it does seem to work...

So does the spectrogram seem to be what you want?