Elliptic Filter PtByPt VI

Owning Palette: Filters PtByPt VIs

Requires: Full Development System

Generates a digital elliptic filter by calling the Elliptic Coefficients VI.

The Elliptic Filter PtByPt VI is similar to the Elliptic Filter VI.

Note  By default, reentrant execution is enabled in all Point By Point VIs.

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	initialize, when TRUE, initializes the internal state of the VI.
	filter type specifies the passband of the filter. 0 Lowpass 1 Highpass 2 Bandpass 3 Bandstop
	passband ripple is the ripple in the passband. passband ripple must be greater than 0 and expressed in decibels. The default is 1.0. If passband ripple is less than or equal to 0, the VI sets the output filter data to 0 and returns an error.
	x is the input signal to filter.
	sampling freq: fs is the frequency in Hz at which you want to sample x and must be greater than 0. The default is 1.0 Hz. If sampling freq: fs is less than or equal to 0, this VI sets Filtered x to 0 and returns an error.
	high cutoff freq: fh is the high cutoff frequency in Hz. The default is 0.45 Hz. 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.
	low cutoff freq: fl is the low cutoff frequency in Hz and must observe the Nyquist criterion. The default is 0.125 Hz. If low cutoff freq: fl is less than or equal to 0 or greater than half the value of sampling freq: fs, the VI sets Filtered x to 0 and returns an error. When filter type is 2 (Bandpass) or 3 (Bandstop), low cutoff freq: fl must be less than high cutoff freq: fh.
	stopband attenuation must be greater than 0. stopband attenuation must be expressed in decibels. The default is 60.0. If stopband attenuation is less than or equal to 0, the VI sets Filtered x to 0 and returns an error. Note  If the filter order is high, this VI uses a higher attenuation than the value of stopband attenuation to design the filter.
	order specifies the filter order and must be greater than 0. The default is 2. If order is less than or equal to 0, the VI sets Filtered x to 0 and returns an error.
	Filtered x contains the result of filtering the input sequence x by convolution.
	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.

Elliptic Filter PtByPt Details

The values for high cutoff freq: fh and low cutoff freq: fl 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.