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Re: Response delay in Vibration Data and FFT graph and memory full operation

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Re: Response delay in Vibration Data and FFT graph and memory full operation

 

Hi all,

       I am acquiring the vibration signal from the stored data in the form of TDMS format

       I am designing an application based on vibration data by applying the signal processing techniques like FFT. In this application i don't want to use any DAQ system or DAQ max system. Just by using the file path i want design an VI

       I am facing few problems as described below:

  1. There is a delay in response of vibration data in waveform graph after the VI runs for sometime
  2. FFT response is been delayed too
  3. Elements in queue goes on increasing
  4. While executing the program it displays the error as "Not enough memory to complete this operation"if i click ok it shows memory is full. How do i reduce this error
  5. In my VI when i choose an file after executing the program the file is corrupted and total data is missing in the tdms file

      What actually i need is 

  1. Implementation of signal processing technique to vibration data
  2. implementation of plotting total channel response and plotting each individual channel response , for example i want to display the channel response graph by selecting the particular channel, according to channel selection it should displays the graph

Any suggestions how to go about this

 

Regards

Sowjanya

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Re: Response delay in Vibration Data and FFT graph and memory full operation

Hi Sowjana,

 

when I answered your personal message I suggested to create your own thread in this board instead of highjacking an old one…

 

1. There is a lot "interesting" code in your VI:

- why do you mix TDMS functions with ReadSpreadsheetFile function?

- why do you use GPIB-Clear with the path of your file as input?

- why do you initialize the queue as "waveform data", but write a plain 1D array into the queue?

- which delay do you see? Can you define "after sometime"?

 

2. When the data is delayed in the producer loop, then the consumer loop will lag too…

 

3. because you are filling the queue much faster than you can process the queue elements!

 

4. Simple solution: don't fill up the memory so fast! Limit the queue length to reasonable sizes as a quick (and dirty) solution…

 

5. See my question for point 1…

Best regards,
GerdW
CLAD expired, using 2009SP1 + LV2011SP1 + LV2017 (+LV2018 sometimes) on Win7+cRIO
Kudos are welcome Smiley Wink

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Re: application development for vibration data processing

Hi all,

    I want to develop an application based on vibration data by using FFT. In this application i am reading the vibration data in TDMS format , here the file size is approximately 414MB, To this TDMS file i want apply arrays and FFT technique ,because from this application i want to calculate the following points as described below

  1. calulating the frequency response for the vibration data, here vibration data is x- axis is time and y- axis is acceleration this should be represent in frequency response as frequency vs amplitude
  2. plotting the total channel response and plotting the individual channel data , when i select a particular channel it should show the plot according to channel selection and it should also displays the values of the channel.  For example like TDMS file viewer we select a channel data it displays the data according to channel selection. similarly i want to plot channel data like that

  In my application i don' t want to use any hardware equipments , just by using basic labview toolkit i want to develop an application

 Is it possible to develop an application like this, if possible how can i go about this 

Any Suggestion

 

Regards

Sowjanya

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Message 3 of 8
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Re: application development for vibration data processing

Hi Sowjanya,

 

why do you keep hijacking old threads? Please keep YOUR discussion in YOUR thread!

Best regards,
GerdW
CLAD expired, using 2009SP1 + LV2011SP1 + LV2017 (+LV2018 sometimes) on Win7+cRIO
Kudos are welcome Smiley Wink

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Re: application development for vibration data processing

hi all, 

   i am not hijacking any thread. Just few hours ago whatever post i posted on discussion form is my project. may be my project is similar to old thread . As i am new to labview i dont know how to build an application based on vibration data

   for that i need some help to start my application. yes i referred to some old threads because to see how they implement the vibration data to various techniques

   By seeing that application i got some idea about implementation of data . for further process i am asking help in discussion forum

   If any one hurts i am sorry

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Accepted by topic author sowji25
01-03-2018 12:37 AM

Re: application development for vibration data processing

Hi Sowjanya,

 

i want to calculate the following points as described below

1. calulating the frequency response for the vibration data, here vibration data is x- axis is time and y- axis is acceleration this should be represent in frequency response as frequency vs amplitude

2. plotting the total channel response and plotting the individual channel data , when i select a particular channel it should show the plot according to channel selection and it should also displays the values of the channel.  For example like TDMS file viewer we select a channel data it displays the data according to channel selection. similarly i want to plot channel data like that

So you already know what you want - that's good!

All you need to do is to program all your requirements… Smiley Very Happy

 

You need to learn:

- how to read a TDMS file and parse it's meta data (like channel names)

- how to create a selection list from the channel names you read from your TDMS file

- how read the data from your file according to the selection in this channel list

- how to apply FFT on it

- how to plot the FFT results

For all those steps you will find example VIs in the example finder in LabVIEW.

And I recommend to do all those steps one by one to learn and understand them before putting all of them into your final VI(s)!

Best regards,
GerdW
CLAD expired, using 2009SP1 + LV2011SP1 + LV2017 (+LV2018 sometimes) on Win7+cRIO
Kudos are welcome Smiley Wink

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not enough memory to complete this operation

when i tried to plot the multiple channel data by using array it showing not enough memory to complete this operation 

 

How can i go about this ?

Any suggestions

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Re: not enough memory to complete this operation

Hi Sowjana,

 

again I moved your message from an old thread into your own one…

 

when i tried to plot the multiple channel data by using array it showing not enough memory to complete this operation How can i go about this ?

When you get "out of memory" then the waveforms are too big. What is the size of your TDMS file? How many samples do those waveforms contain?

 

Solution: read only parts of the whole waveforms to plot them…

Best regards,
GerdW
CLAD expired, using 2009SP1 + LV2011SP1 + LV2017 (+LV2018 sometimes) on Win7+cRIO
Kudos are welcome Smiley Wink

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