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pt by pt to array

Hey Guys i have been working on accessing the data from usb(serial) so the values are coming point by point so for processing its fft point by point vis should be used but i want to use the sound n vibration tool kit vi of fft but its not working as only one point is plotted at a time?\

 

 

Anybody may help with this difficulty? 

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Message 1 of 17
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hello,

 

can you try something like that ?

 

@+

 

Tinnitus

 

CLAD / Labview 2011, Win Xp
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Message 2 of 17
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Hey thanks for your reply , You got what actually my problem is ,but the vi which you attached is not working, FFT graph is not giving output, if you will repost that example i ll appreciate it, thanks....
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Message 3 of 17
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Hi,

 

just set the tampon value to some other positive value. You will get the graph then.

 

regards,

Vaibhav

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Message 4 of 17
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hello,

 

has said previously, i forgot to set default value to tampon "buffer" command 

 

try 1001 for example , is the number of values , the vi store before displaying somthing

 

Best regards

 

Tinnitus

 

CLAD / Labview 2011, Win Xp
------------------------------------------------------
Mission d'une semaine- à plusieurs mois laissez moi un MP...
RP et Midi-pyrénées .Km+++ si possibilité de télétravail

Kudos always accepted / Les petits clicks jaunes sont toujours appréciés
Don't forget to valid a good answer / pensez à valider une réponse correcte
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Message 5 of 17
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sorry: As said

 


Message Edité par tinnitus le 12-26-2008 07:21 AM
Message Edité par tinnitus le 12-26-2008 07:24 AM
CLAD / Labview 2011, Win Xp
------------------------------------------------------
Mission d'une semaine- à plusieurs mois laissez moi un MP...
RP et Midi-pyrénées .Km+++ si possibilité de télétravail

Kudos always accepted / Les petits clicks jaunes sont toujours appréciés
Don't forget to valid a good answer / pensez à valider une réponse correcte
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Message 6 of 17
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Thanks guys for your support i got it by the method:smileyhappy:
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Message 7 of 17
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Instead of constantly building and resizing arrays, you should setup a fixed size array buffer that you then fill and transform as you go.

 

Here's a very simple draft.

 

How fast does the data arrive? Are the points equally spaced in time? What frequencies are you interested in?

 

You need to adjust the buffer size to cover the freqeuncies of interest. You might also want to add a windowing function before the transform to minimize spectral leakage. Most likely your window is not an integer multiple of the wavelenghts.

 

 

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Message 8 of 17
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hello

 

nice tip the sliding windows, i 'll remember this for a futur app

 

see you

 

Tinnitus

 

 

Message Edité par tinnitus le 12-27-2008 04:05 PM
CLAD / Labview 2011, Win Xp
------------------------------------------------------
Mission d'une semaine- à plusieurs mois laissez moi un MP...
RP et Midi-pyrénées .Km+++ si possibilité de télétravail

Kudos always accepted / Les petits clicks jaunes sont toujours appréciés
Don't forget to valid a good answer / pensez à valider une réponse correcte
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Message 9 of 17
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Hello all,

This thread seems the closest to what I am looking to achieve, though I just dont seem to be able to get it, and after reading about action engines,  queues, and various attempts, I believe there must be a simple way which I am missing.

 

I have a while loop with some pt by pt signal generation blocks creating data continuously.

I would like to package this data into a 1000 point array, which I will pass to a waveform graph after some processing....like packaged snapshots of the data stream.

 

I am thinking it would be most efficient to only pass this 1000 pt array once every 1000 pts for processing and display, but I cannot figure how to make this 1 every 1000 loop event happen ..either within or outside the while loop ?

 

As well, another question is , how to pass this array to a seperate while loop for processing and display in an asynchronous manner eg. for display to a user..like a scope screen, where it doesnt matter about the update rate and it can run more slowly than the main pt by pt loop.

 

Any hints or links would be much appreciated.

 

Thanks,

carloman

 

ps: I have eradicated many property nodes since reading " the wire is the data" and other posts, and am hoping to take my LV skills, or lack thereof, one notch higher

 

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Message 10 of 17
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