FIR Windowed Filter (Not in Base Package)

Filters the input data sequence, X, using the set of windowed FIR filter coefficients specified by the sampling freq: fs, low cutoff freq: fl, high cutoff freq: fh, and number of taps. Details  Example

	filter type specifies the passband of the filter. 0 Lowpass 1 Highpass 2 Bandpass 3 Bandstop
	X is the input signal to filter.
	sampling freq: fs is the sampling frequency and must be greater than zero. The default is 1.0. If it is less than or equal to zero, the VI sets Filtered X to an empty array and returns an error.
	low cutoff freq: fl is the low cutoff frequency and must observe the Nyquist criterion. The default is 0.125. If low cutoff freq : fl is less than zero or does not meet the Nyquist criterion, the VI sets Filtered X to an empty array and returns an error.
	high cutoff freq: fh is the high cutoff frequency. The VI ignores this parameter when filter type is 0 (Lowpass) or 1 (Highpass). When filter type is 2 (Bandpass) or 3 (Bandstop), high cutoff freq: fh must be greater than low cutoff freq: fl and observe the Nyquist criterion.
	taps determines the total number of FIR coefficients and must be greater than zero. The default is 25. If taps is less than or equal to 0, the VI sets Filtered X to an empty array and returns an error. taps must be odd for highpass and bandstop filters.
	window specifies the type of smoothing window. Smoothing windows decrease ripple in the filter passband and improve the ability of the filter to attenuate frequency components in the filter stopband. 0 None 1 Hanning 2 Hamming 3 Triangular 4 Blackman 5 Exact Blackman 6 Blackman-Harris 7 Kaiser-Bessel 8 Flat Top
	Filtered X is the output array of filtered samples. Filtered X has an associated index delay caused by the convolution operation. The delay is given by the following equation.
	error returns any error or warning from the VI. You can wire error to the Error Cluster From Error Code VI to convert the error code or warning into an error cluster.

FIR Windowed Filter Details

The values for low cutoff freq: fl and high cutoff freq: fh must observe the following relationship.

0 < f₁ < f₂ < 0.5f_s

where f₁ is low cutoff freq: fl, f₂ is high cutoff freq: fh, and f_s is sampling freq: fs.

Example

Refer to the FIR Windowed Filter Design VI in the labview\examples\analysis\fltrxmpl.llb directory for an example of using the FIR Windowed Filter VI.