save million datas in one sec

[Mystogan]

any .vi example with pre writing to binary file?

[altenbach]

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@Mystogan wrote:

any .vi example with pre writing to binary file?

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First, let's clean up the mess.

• In your toplevel VI, you already write to a binary file in the lower left corner. Do something similar.
• How is this called? Does it get called once per second, creating a new histogram with every call?
• Are you overwriting the same file with each call?
• Your histogram code has way too much garbage. Looks like a donwconversion from an in place element structure to an old LabVIEW version. You can delete the inner while loops.
• What is the purpose of the FOR loop in the save subVI. All it does is thrash the memory. Can you explain why it is there?
• ....

[Mystogan]

@altenbach: thanks for the quick reply.

The purpose of my last question here is actually not regarding the first post in this thread anymore. But I tought, this is the basic that I still dont understand. Thats why I'm trying to ask for example in this thread.

What I'm trying to do is:

1. Acquiring data samples with a digitizer (done)

2. Save the data that I got from the digitizer into a file, and reffering to the sampling frequency of the digitizer (ex.: 4MSamples), which means it would plot 4 million points in 1 sec running, right? If I would save the points in a file, what is the best way to do it?

I've tried to simulate it by generating sinus wave using sine waveform.vi with random amplitudes in a while loop with certain delay (in test CIC2.vi), then I wanted to save the generated waves (array of time and amplitude) into a file. Then I increase the sample rate and the number (ex.:1M ), and decrease the delay to 250ms (I'm trying to get 4Million points in 1 sec).

When I do this, and look at the task manager, the memory allocated for labview is increasing very fast until it reach a limit, then labview gives me this: "memory is full". Im not even saving the points yet.

Simply said: I want to save acquired 4MSamples/sec without getting "memory is full", what is the best way to do it?

regards,

Yan.

[Mystogan]

hi everyone,

I think I have found want I need. Just using combination of examples:

- niScope EX Fetch Forever.vi

- TDMS Data write.vi

But maybe I could get a little help about reading it back to work with the datas. With using TDMS I can save million points every seconds, but to read it back in one big file seems very problematic with memory. I've been looking here (http://forums.ni.com/t5/LabVIEW/Memory-usage-problem-with-TDMS-files/td-p/1907261). But seems there is no help yet either. 

Maybe anyone can guide me to any tutorial with data splitting or anything like that?

regards,

Yan.