Jump to content

How do you tell when one scan ends and the next one starts?


Recommended Posts

Goal: To use the built in acquire process display n scan template to get fft of one input and a dc value of the rest using a AT-MIO-16XE card in Labview 6.1.

Issue: Read one scan create fft (amplitude vs frequency), Max & Min and Dc values of the rest.

How to determine when one scan is finished and the next one starts, so I can reset the Max/min and basic DC/RMS object and the min max of the FFT amplitude at ever scan .

Inputs:

Fast - Dynamic pressure - need to plot amplitude verses frequency

Slow - temperatures and pressures - just need average Dc value

currently solving these other issues,

FFT does not function properly (only looking at only one half of spectrum)

need to convert 'save to spreadsheet' to save to string to file (to much overhead opening file every time)

Thanks for your help

Link to comment

QUOTE (carleton_hanson @ Mar 12 2008, 11:02 AM)

Goal: To use the built in acquire process display n scan template to get fft of one input and a dc value of the rest using a AT-MIO-16XE card in Labview 6.1.

Issue: Read one scan create fft (amplitude vs frequency), Max & Min and Dc values of the rest.

How to determine when one scan is finished and the next one starts, so I can reset the Max/min and basic DC/RMS object and the min max of the FFT amplitude at ever scan .

Inputs:

Fast - Dynamic pressure - need to plot amplitude verses frequency

Slow - temperatures and pressures - just need average Dc value

currently solving these other issues,

FFT does not function properly (only looking at only one half of spectrum)

need to convert 'save to spreadsheet' to save to string to file (to much overhead opening file every time)

Thanks for your help

Sounds like the scanning business you propose is not needed and the root problem is FFT "not working." You should solve the FFT. I don't ever mess with that so someone else will have to chime in.

If you unpack the write to sprdsht vi you can pull the open and close out of the loop. However, I don't understand why you are writing to the spreadsheet every loop iteration. Why not keep the data in an array (shift register and build array) and write it out when you are done so there is no file accessing at all while doing the AI Read.

Mike

Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Unfortunately, your content contains terms that we do not allow. Please edit your content to remove the highlighted words below.
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.