DFD Build Filter from Transfer Function VI

Digital Filter Design VIs and Functions

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Owning Palette: Utilities VIs

Installed With: Digital Filter Design Toolkit

Creates a filter from a transfer function.

Details Examples

Place on the block diagram

Find on the Functions palette

numerator specifies the numerator polynomial of the transfer function in ascending order of z^–1.

denominator specifies the denominator polynomial of the transfer function in ascending order of z^–1. The default is 1, which means this VI builds an FIR filter.

error in describes error conditions that occur before this VI or function runs. The default is no error. If an error occurred before this VI or function runs, the VI or function passes the error in value to error out. This VI or function runs normally only if no error occurred before this VI or function runs. If an error occurs while this VI or function runs, it runs normally and sets its own error status in error out. Use the Simple Error Handler or General Error Handler VIs to display the description of the error code. Use error in and error out to check errors and to specify execution order by wiring error out from one node to error in of the next node.

	status is TRUE (X) if an error occurred before this VI or function ran or FALSE (checkmark) to indicate a warning or that no error occurred before this VI or function ran. The default is FALSE.
	code is the error or warning code. The default is 0. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code.
	source specifies the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning. The default is an empty string.

filter out returns a new filter.

error out contains error information. If error in indicates that an error occurred before this VI or function ran, error out contains the same error information. Otherwise, it describes the error status that this VI or function produces. Right-click the error out front panel indicator and select Explain Error from the shortcut menu for more information about the error.

	status is TRUE (X) if an error occurred or FALSE (checkmark) to indicate a warning or that no error occurred.
	code is the error or warning code. If status is TRUE, code is a nonzero error code. If status is FALSE, code is 0 or a warning code.
	source describes the origin of the error or warning and is, in most cases, the name of the VI or function that produced the error or warning.

DFD Build Filter from Transfer Function Details

The transfer function of a filter is defined by the following equation:

where	z is a complex variable
	b is the set of coefficients of the numerator polynomial, also known as the forward coefficients
	a is the set of coefficients of the denominator polynomial, also known as the reverse coefficients
	N is the numerator order
	M is the denominator order

The default value of denominator is 1.00, which means this VI builds an FIR filter.

Examples

Refer to the following VIs for examples of using the DFD Build Filter from Transfer Function VI:

Build an Exponentially Weighted Moving Average Filter VI: labview\examples\Digital Filter Design\Getting Started\Design Filters
Open example Browse related examples
Create Filter from Transfer Function VI: labview\examples\Digital Filter Design\Getting Started\Design Filters
Open example Browse related examples

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