Pole-Zero Placement Express VI

Digital Filter Design VIs and Functions

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Pole-Zero Placement Express VI

Owning Palette: Filter Design VIs

Installed With: Digital Filter Design Toolkit

Adds, deletes, and moves poles and zeroes in a filter.

You can load a filter from an existing file.

Dialog Box Options

Block Diagram Inputs

Block Diagram Outputs

Place on the block diagram

Find on the Functions palette

Dialog Box Options

Parameter	Description
Zeroes	Specifies the properties for each zero in the filter. Contains the following options: Real—Specifies the real part value if coordinates are rectangular, or the radius value if coordinates are polar. Imaginary—Specifies the imaginary part value if coordinates are rectangular, or the angle value if coordinates are polar. Is real?—Makes the specified pole or zero point real if you place a checkmark in the checkbox. Is linear phase pair?—Makes the specified pole or zero a linear phase pair if you place a checkmark in the checkbox. On unit circle?—Places the pole or zero point on the unit circle if you place a checkmark in the checkbox. Order—Specifies the order of the pole or zero. The value of Order must be an integer greater than zero. The default is 1.
Poles	Specifies the properties for each pole in the filter. Contains the following options: Real—Specifies the real part value if coordinates are rectangular, or the radius value if coordinates are polar. Imaginary—Specifies the imaginary part value if coordinates are rectangular, or the angle value if coordinates are polar. Is real?—Makes the specified pole or zero point real if you place a checkmark in the checkbox. Is linear phase pair?—Makes the specified pole or zero a linear phase pair if you place a checkmark in the checkbox. On unit circle?—Places the pole or zero point on the unit circle if you place a checkmark in the checkbox. Order—Specifies the order of the pole or zero. The value of Order must be an integer greater than zero. The default is 1.
Settings	Contains the following options: Gain—Sets the gain of the filter manually. You can use this control only if you remove the checkmark from the Normalized gain checkbox. Normalized gain—Specifies if this Express VI automatically adjusts the gain of the filter. The default contains a checkmark in the checkbox, which specifies that this Express VI adjusts the gain so the maximum response is 1.0 (0 dB). Remove the checkmark from the checkbox to adjust the gain manually with the Gain control. Sampling frequency—Specifies the sampling frequency in hertz. This input must contain a value greater than zero. The default is 1 Hz. Coordinates—Specifies whether this Express VI displays poles and zeroes in rectangular or polar coordinates. The default is rectangular coordinates.
Load Filter from File	Opens a file dialog you can use to select a file of a filter that loads into this Express VI.
Zero	Specifies the color of the zeroes in the Z Plane plot. The default is blue. Click the color box next to the parameter name to select a different color.
Pole	Specifies the color of the poles in the Z Plane plot. The default is red. Click the color box next to the parameter name to select a different color.
Delete Selected	Deletes the selected pole or zero from the filter.
Add Zero	Adds a zero to the filter.
Add Pole	Adds a pole to the filter.
Z-Plane	Plots the number and location of poles and zeroes.
Magnitude Response	Plots the filter magnitude response.
Magnitude in dB	Specifies whether this Express VI uses decibels or a linear scale in the magnitude plot. If a checkmark is in the checkbox, this Express VI converts linear magnitude response to decibels.

Block Diagram Inputs

Parameter	Description
error in (no error)	Describes error conditions that occur before this VI or function runs.

Block Diagram Outputs

Parameter	Description
filter out	Returns the 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.

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