TFA Configure Spectrogram Indicator VI

LabVIEW 2014 Advanced Signal Processing Toolkit Help

Edition Date: June 2014

Part Number: 372656C-01

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Owning Palette: Utilities VIs

Requires: Advanced Signal Processing Toolkit

Displays the spectrogram of a signal on an intensity graph. Wire data to the color table input to determine the polymorphic instance to use or manually select the instance.

You can save the time-dependent 2D array to a text file for use in another software environment. The resulting text file contains only Z values and does not retain the time axis information or the frequency axis information. You can use the TFA Get Time and Freq Scale Info VI to compute the time scale information and the frequency scale information of the time-frequency representation.

Examples

Use the pull-down menu to select an instance of this VI.

TFA Configure Spectrogram Indicator (Predefined Color Table)

reference of TF spectrogram indicator specifies the reference of TF spectrogram indicator. If you do not wire this input, this VI does not set the scale information and color table for TF spectrogram indicator.
dB on? specifies to display the spectrogram in decibels or in a linear scale. If dB on? is TRUE, this VI returns the spectrogram in decibels. If dB on? is FALSE, this VI returns the spectrogram in a linear scale. The default is FALSE.
spectrogram specifies the quadratic time-frequency representation of a signal. Each row corresponds to the instantaneous power spectrum at a certain time.
scale info specifies the time scale information and the frequency scale information of the time-frequency representation.
ignore timestamp? specifies whether this VI forces the timestamp of the input signal to 0 so you can define the limit signals relative to the beginning of the input signal. The default is FALSE, which means this VI uses the timestamp in scale info.
error in describes error conditions that occur before this node runs. This input provides standard error in functionality.
color table specifies the color table of TF spectrogram indicator.

0Rainbow (default)—Displays the maximum in red and the minimum in purple.
1Inverse gray—Displays the maximum in black and the minimum in white.
2Gray—Displays the maximum in white and the minimum in black.
TF spectrogram indicator displays the spectrogram on an intensity graph. The x–axis represents time, and the y–axis represents frequency. The color indicates the energy of the signal.
error out contains error information. This output provides standard error out functionality.

TFA Configure Spectrogram Indicator (Customized Color Table)

reference of TF spectrogram indicator specifies the reference of TF spectrogram indicator. If you do not wire this input, this VI does not set the scale information and color table for TF spectrogram indicator.
dB on? specifies to display the spectrogram in decibels or in a linear scale. If dB on? is TRUE, this VI returns the spectrogram in decibels. If dB on? is FALSE, this VI returns the spectrogram in a linear scale. The default is FALSE.
spectrogram specifies the quadratic time-frequency representation of a signal. Each row corresponds to the instantaneous power spectrum at a certain time.
scale info specifies the time scale information and the frequency scale information of the time-frequency representation.
ignore timestamp? specifies whether this VI forces the timestamp of the input signal to 0 so you can define the limit signals relative to the beginning of the input signal. The default is FALSE, which means this VI uses the timestamp in scale info.
error in describes error conditions that occur before this node runs. This input provides standard error in functionality.
color table specifies a 256-element array of colors that defines the color table of TF spectrogram indicator. Refer to the Create IntGraph Color Table VI in the labview\examples\general\graphs\intgraph.llb for an example of how to create a customized color table.
TF spectrogram indicator displays the spectrogram on an intensity graph. The x–axis represents time, and the y–axis represents frequency. The color indicates the energy of the signal.
error out contains error information. This output provides standard error out functionality.

Examples

Refer to the following VIs for examples of using the TFA Configure Spectrogram Indicator VI:

  • Blood Flow Measurement VI: labview\examples\Time Frequency Analysis\TFAApplications
  • Heart Sound TFA VI: labview\examples\Time Frequency Analysis\TFAApplications
  • Liquefaction Detection VI: labview\examples\Time Frequency Analysis\TFAApplications
  • Cross Term VI: labview\examples\Time Frequency Analysis\TFAGettingStarted
  • Time-Frequency Resolution VI: labview\examples\Time Frequency Analysis\TFAGettingStarted
  • Color Tables for Displaying the Spectrogram VI: labview\examples\Time Frequency Analysis\TFAGettingStarted

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