Home > Support > NI Product Manuals > LabVIEW Communications System Design Suite 1.0 Manual

    Filters a sequence of samples using the cascade form of a specified IIR filter. This node is similar to IIR Cascade Filter except that you specify the initial conditions for this node.

    Programming Patterns

    This node requires the output coefficients from one of the IIR coefficient design nodes: Butterworth Coefficients, Bessel Coefficients, Chebyshev Coefficients, Elliptic Coefficients, or Inv Chebyshev Coefficients.



    An array of samples to filter.

    Default: Empty array


    IIR filter cluster

    The cascaded form of IIR filter coefficients. Wire the output of one of the IIR coefficient design nodes to this input.


    filter structure

    An enum value that selects IIR second-order or fourth-order filter stages.

    IIR 2nd Order

    Selects the IIR second-order filter stage.

    IIR 4th Order

    Selects the IIR fourth-order filter stage.

    Default: IIR 2nd Order


    reverse coefficients

    The reverse coefficients of the IIR cascade filter.


    forward coefficients

    The forward coefficients of the IIR cascade filter.


    initial filter state

    The initial internal filter state.

    If this input is not the same size as the reverse coefficients array in the IIR filter cluster, the array resizes internally and initializes to zero before the IIR filtering operation. The filtering occurs internally and the filter state is maintained until all samples in array x have been passed through the filter. The final filter state array is then passed to the array indicator, final filter state.



    filtered x

    An array of filtered samples.


    final filter state

    The final, internal filter states.

    To filter samples continuously, you can wire this value to the initial filter state input of the next call of this node.



    A value that represents any error or warning that occurs when this node executes.