Applying Signal Operators by Commands

You can insert and edit a number of signal operators by commands.

Important: You can add signal operator probes on signals in watchlists as well.

This task shows you how to:

Before you begin: Display curves in a plot.
See Also
About Signal Operators

Insert a Minimum, Maximum, Slew Rate, Discrete Difference, or a Mean Signal Operator

You can insert a number of signal operators where only the interval must be specified.

Note: You can apply these signal operators also on curves that are plotted against independent variables other than time, if the independent variables are rising over time.

  1. Right-click anywhere in a plot and select Edit > Create signal operator.
    The Create Signal Operator dialog box is displayed.
  2. Optional: Enter a name of the signal operator in the Name field.

    By default the name is the type of the signal operator, selected in the next step.

  3. Click the curve.
    The corresponding signal name appears in the Curve field.
  4. In the Type: list, select any of the following signal operators.

    • Minimum
    • Maximum
    • Arithmetic mean
    • Rectified mean
    • Root mean square
    • AC Coupled RMS
    • Slew rate
    • Discrete difference
    • Moving Average

  5. Select the range over which the operator is applied:
    1. In the Minimum X: field, enter the minimum x value.

      By default, the minimum x value is the value (usually time) at the start time of the simulation.

    2. In the Maximum X: field, enter the maximum x value.

      By default, the maximum x value is the value (usually time) at the stop time of simulation.

  6. For the moving average signal operator, you can do the following:
    1. Optional: In the Interval length: field, you can change the interval length value.
    2. Optional: To compute and display first-order derivatives, activate Differentiate signal.
  7. Click OK.
    The signal operator is displayed in the chart, except for the discrete difference signal operator, it is displayed in a new chart.

Insert a First Harmonic or a Total Harmonic Distortion Signal Operator

You can insert frequency-based signal operators for which also the period must be specified.

  1. Right-click anywhere in a plot and select Edit > Create signal operator.
    The Create Signal Operator dialog box is displayed.
  2. Optional: Enter a name of the signal operator in the Name field.

    By default the name is the type of the signal operator.

  3. Click the curve.
    The corresponding signal name appears in the Curve field.
  4. In the Type: list, select any of the following signal operators.

    • First harmonic
    • Total harmonic distortion

  5. Select the range over which the operator is applied:
    1. In the Minimum X: field, enter the minimum x value.

      By default, the minimum x value is the value (usually time) at the start time of the simulation.

    2. In the Maximum X: field, enter the maximum x value.

      By default, the maximum x value is the value (usually time) at the stop time of simulation.

  6. In the Period length: field, enter the period length.

    By default, the period length is the length of the simulation.

    Note: The period can be computed by clicking Compute.

  7. For the total harmonic distortion signal operator, you can enter a value in the Number of harmonics field.

    The default value appears when the period length is entered computed.

  8. In the Interval length: field, you can enter the interval length value.
    The interval length together with the horizontal range gives the Number of points.
  9. Select Window presentation.

    Default is Rectangular, which gives equal weight to all points. Other alternatives are Hamming, Hann, and FlatTop.

  10. Click OK to display the signal operator in the plot.

Insert a Fast Fourier Transformation Signal Operator

You can insert a Fast Fourier Transformation (FFT) signal operator.

  1. Right-click anywhere in a plot and select Edit > Create signal operator.
    The Create Signal Operator dialog box is displayed.
  2. Optional: Enter a name of the signal operator in the Name field.

    By default the name is the type of the signal operator.

  3. Click the curve.
    The corresponding signal name appears in the Curve field.
  4. In the Type: list, select Fast Fourier Transformation.
  5. Select the range over which the operator is applied:
    1. In the Minimum X: field, enter the minimum x value.

      By default, the minimum x value is the value (usually time) at the start time of the simulation.

    2. In the Maximum X: field, enter the maximum x value.

      By default, the maximum x value is the value (usually time) at the stop time of simulation.

  6. In the Max. Frequency: field, you can enter the maximum frequency to plot.

    The maximum number that can be selected is displayed after the field.

  7. Select Window presentation.

    Default is Rectangular, which gives equal weight to all points. Other alternatives are Hamming, Hann, and FlatTop.

  8. In the Interval length: field, you can enter the interval length value.
    The interval length together with the horizontal range gives the Number of points.
  9. Click OK to display the signal operator in a separate plot.

Edit Signal Operators

You can edit an existing signal operator.

  1. You can edit an existing signal operator by the dialog box of the signal operator. You can display the dialog box in two ways:
    • Double-click the signal operator.
    • Right-click the signal operator and select Edit.
    The corresponding signal operator dialog box appears.
  2. Edit the values in the dialog box. See previous sections.
  3. Click OK to validate the changes.
  4. You can delete a signal operator by right-clicking it and select Delete.