Digital FIR Filter VI

This VI filters the signal(s) in a waveform array according to the FIR filter specifications and optional FIR filter specifications arrays. If you are filtering multiple waveforms, the VI applies a different filter to each of the input waveforms and maintains a separate filter state for each waveform. The VI uses the optional FIR filter specifications only if Filter topology is FIR by Specification or Windowed FIR. You do not need to wire reset filter. This VI resets itself the first time it is called.

The Digital FIR Filter VI can perform single-channel measurements in both one-shot mode (single call) and continuous mode (multiple calls with history). It can perform multi-channel measurements only in one-shot mode. If you want to make multiple-channel measurements in continuous mode, either use the multichannel instance of this VI or use one instance of this VI per channel.

The single-channel instance of this VI is intended primarily for continuous processing of a single channel. Do not generalize this behavior to the multi-channel case, typically by using this single-channel VI in a For Loop to continuously process multiple channels by indexing an array of waveforms.

The single-channel instance of this VI maintains internal state information for a single channel only. Calling this VI to process another channel without clearing the history using the reset filter control results in an unexpected behavior of this VI because the internal state information is passed from one channel to another.

Examples

Refer to the following example files included with LabVIEW.

• labview\examples\Signal Processing\Waveform Conditioning\FIR Filtering and Response.vi
• labview\examples\Signal Processing\Waveform Conditioning\FIR Filtering Using Optional Specs.vi