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Continuously plotting and analyzing from file

Hi everyone,

 

I have a following problem. I have large binary files with measurement data. I'm making some kind of offline analysis - I must be able to play and analyses my  waveform, control speed of plotting, start from specified position on record  and change X scale range. I'm doing FFT analysis,  Zoom FFT,  Integration and many more. My program runs in while loop so I'm sending data in blocks. The problem is if I send , for example,1 second of data to Integration vi, I will get some kind of transient on the beginning of waveform for every block. I try to hide that part of waveform (offset on chars), but this make further  analysis  little bit too complex. I'm doing also an online analysis.

 

Is there any advised technique for this type of problem ? Running analysis on whole data is not an option.  I have some ideas but they are not so much elegant. So  I would like to hear some suggestions. 

 

Thanks,

Tomislav

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Message 1 of 6
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Are you using some filter VIs in your aplication?


Besides which, my opinion is that Express VIs Carthage must be destroyed deleted
(Sorry no Labview "brag list" so far)
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Yes, that is source of my problems. I know why I get "transient" on begining of waveform, but I'm not sure yet how to solve that problem.
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I'm using SVL Integration.vi and if I could some way analyses block by block in while loop without that starting transient all my problems would be solved.
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All filters also analog has something called setting time. So then you read your first block of data you will have some artifacts anyway. With some tricks you may remove this also. But as a starter set the init/cont Boolean to true, all time. Then you read the  first data block will have artifacts the rest not. But this again depends on several other settings. But without going to deep into theory try this first

 

 



Besides which, my opinion is that Express VIs Carthage must be destroyed deleted
(Sorry no Labview "brag list" so far)
Message 5 of 6
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Great, that solve that problem. I have much bigger problem with blocks like SVL Integration.vi (see Attachment). I'dont have init/cont Boolean control and this block affects on all my further analysis. I would attach print screen or my VI but it is very large, so one more time:

 

1. SVL Integration block is inside while loop

2. I send data in blocks of variable length as 1-D array of waveform

3. data are read from file or from physical channel

 

Is it even possible to do this inside while loop without using additional number of samples and discarding them after analysis ?

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