Resamples input signal X according to Time using an FIR filter implementation. Wire data to the X input to determine the polymorphic instance to use or manually select the instance.


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Inputs/Outputs

  • cbool.png anti-aliasing? —

    anti-aliasing? specifies whether the input signal undergoes lowpass filtering when LabVIEW downsamples the signal.

    If anti-aliasing? is TRUE (default), this VI protects the resampled signal from aliasing. However, the computation requirements increase during resampling.

  • cbool.png reset? —

    reset? controls the initialization of the internal states. The default is FALSE.

    The first time this VI runs or when reset? is TRUE, LabVIEW initializes the internal states to zero. When reset? is FALSE, LabVIEW initializes the internal states to the final states from the previous call to this instance of this VI. To process a large data sequence consisting of smaller blocks, set this control to TRUE for the first block and to FALSE for continuous filtering of all remaining blocks.

  • c2dcdb.png X —

    X contains the input real signals for resampling. Each row of X contains an input signal. All the signals have the same length. The sampling interval of each signal in X is 1.

  • c1ddbl.png Time —

    Time specifies the time instances for resampling in ascending order.

  • cerrcodeclst.png error in (no error) —

    error in describes error conditions that occur before this node runs. This input provides standard error in functionality.

  • cnclst.png FIR filter specifications —

    FIR filter specifications specifies the minimum values this VI needs to specify the FIR filter.

  • cdbl.png alias rejection (dB) —

    alias rejection (dB) specifies the minimum attenuation level of signal components aliased after any resampling operation. If alias rejection (dB) is less than 48, this VI will use 48 instead. The default is 120.

  • cdbl.png normalized bandwidth —

    normalized bandwidth specifies the fraction of the new sampling rate that is not attenuated. The default is 0.4536.

  • i2dcdb.png Y —

    Y returns the resampled signals. Each row of Y contains a resampled signal that corresponds to the input signal in the same row of X. All the signals have the same length.

  • i1ddbl.png Time Stamps —

    Time Stamps returns the time instance for each sample of every resampled signal in Y. The number of elements in Time Stamps is equal to the number of columns in Y. The contents of the Time input determine the contents of Time Stamps. As a result of the internal state of the resampling filter, Time Stamps might have additional data at the beginning of the array and might lose some data at the end of the array.

  • ierrcodeclst.png error out —

    error out contains error information. This output provides standard error out functionality.

    • To calculate a resampled signal at time t, this VI needs several pieces of original signal data both before and after t. The FIR filter specifications determine the number of pieces of signal data before and after t that this VI needs. If t is close to the end of the input signal, this VI might not have enough data after t to calculate the resampled signal. However, if you use this VI in online applications in which you continuously acquire data, this VI can calculate the resampled signal at t when the next input signal block is available. Therefore, in the first input signal block, Time Stamps loses data for t at the end of the array. In the next input signal block, Time Stamps has t as additional data at the beginning of the array.