Labview 'Summarized' Collecting data Points

[MatthijsHvA]

Dear all,

Currently I am using LabView for my graduating project at the University of Amsterdam. The set-up is that with LabView I make an HP 33120A function generator transmit a Gaussian Pulse into a material thru Piezo Electric Transducers and these transducers also collect the signal. This is then amplified by a Physical Accaustics 1220A pre-amplifier to transfer the signal into a Tektronix DPO2014 oscilloscope, which transfers it in data points to Labview again.

The collection time is set to 125000 points, and here is the problem. It used to work perfectly fine, however now it still collects 125000 data points, of only which 3000 points contain the entire signal. The rest is somehow 0. In other words, the usual response of 125.000 points is now summarized in 3000 points.

Do you have any idea what might be the problem? Or the solution?

With kind regards,

Matthijs

I've added a PDF with the explanation of the VI i'm using.

[MichaelAivaliotis]

Try disabling the Matlab script.

[TCPlomp]

Hi Matthijs,

could you plot the data directly in LabVIEW just to make sure the issue is not the export script?

If I look at the code I see you can use auto-index more efficiently (in some for loops you are appending data all the time, like calculate fidelity). By using auto-indexing LabVIEW will better claim the memory befor the loop runs.

But by reading your desciption it looks like the samplerate is not correctly calculated. I assume the error is in the Measurements for loop . Which of the two signals has the issue (RawSignals or Fidelity)?

You could have a look at the Mat-file IO library for storing the data.

Ton

[MatthijsHvA]

Hi Ton and Michael,

Thank you for your reaction!

The problem already occurs if I just run the collection script without saving anything. And it is about the RawSignals, they contain all the data which is collected from the oscilloscope. 

So, the problem is already dear before the fidelity is being calculated and the data stored to a MatLab file.

Thx again!

[TCPlomp]

Well then I assume that there is an error in the collect data from ossciloscope. You continue to create the 2D array, probably your instrument outputs zeroes if an error has occured.

I would check if the calculations you perform to set the acquisition time is right.

Ton

[MatthijsHvA]

Solution is found. Apparently with windows update the correct drivers  of the oscilloscope were changed. So: Problem solved!

[MatthijsHvA · Accepted solution]

Solution is found. Apparently with windows update the correct drivers  of the oscilloscope were changed. So: Problem solved!

[MichaelAivaliotis]

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@MatthijsHvA wrote:

Solution is found. Apparently with windows update the correct drivers  of the oscilloscope were changed. So: Problem solved!

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Windows Update, updated the oscilloscope driver? That's strange and unexpected.