UltimaSerial WinDaq Add-on: FFT
 

This addon provides real-time FFT display 

 

Features

  1. Multiple FFT sizes: 1024, 2048, 4096,  8192, 16384 and 32768
    • Due to Windaq's memory allocation approach, the following rule should be observed if you wish to use this add-on. 
      • For FFT size of 1024, up to 58 channels can be enabled in Windaq
      • For FFT size of 2048, up to 29 channels can be enabled in Windaq
      • For FFT size of 4096, up to 15 channels can be enabled in Windaq
      • For FFT size of 8192, up to 7 channels can be enabled in Windaq
      • For FFT size of 16384, up to 3 channels can be enabled in Windaq
      • For FFT size of 32768, only 1 channel can be enabled in Windaq 
    • DC component of the signal can be removed before FFT is performed (Check AC option)
  2. Three scaling options for the frequency axis:

    • Standard Frequency Scaling, each pixel line represents one frequency component and you may use the horizontal scroll bar to scroll the interested frequency range into view.

    • Logarithmic Frequency Scaling,  to fit the full frequency range to the charting area with a logarithmic scale. This is perfect to generate a frequency response like what you see in an audio engineering chart. If Chart persist is checked, you may run a sweeping signal through the whole frequency range and see a frequency response chart of your sensor.

    • Full-fit Frequency Scaling,  to fit the full frequency range to the charting area with a linear scale

  3. While acquiring spectrum, you may
    1. use the left mouse button to drag the waveform up and down
    2. double-click the left of right mouse buttons to change the scaling of the waveform. 
    3. adjust the Analog oscilloscope-like persistence control to study the trend of the spectrum (Refer to the above screen shot for visual effect)
    4. push down the right mouse button to enable a vertical cursor to exam to the waveform.
    5. click on AutoSet button to bring a weak signal into sight immediately
  4. Once you stop the live frequency display, you may 
    1. push down the left mouse button on the chart to enable a vertical cursor and drag it around to study the spectrum
    2. push down the right mouse button on the chart to enable a cross hair and drag it around to study the spectrum
  5. Intelligent Channel Select: Highlight/Select a channel in Windaq and fire up this Windaq add-on

To Use WinDaq Add-on FFT

  1. Start WinDaq, and select (highlight) a channel 

  2. Invoke Windaq->View->Add-ons->FFT, and the selected channel will be used as the default channel. 

  3. Do not change WinDaq's configurations while WinDaq add-ons are running

Configuration file

C:\Windows\wdqfft.ini

If you can't find it there, you may need to look in C:\Users\...\AppData\Local\VirtualStore\Windows

 

Last update: 07/22/24

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