Discrete Zero-Pole-Gain (Simulation Module and Control Design Toolkit)
Implements a system model in discrete zero-pole-gain form. You define the system model by specifying the Zeros, Poles, and Gain of the zero-pole-gain equation. Details
| Dialog Box Options |
| Block Diagram Inputs |
| Block Diagram Outputs |
Dialog Box Options
| Parameter | Description |
|---|---|
| Polymorphic instance | Specifies whether this function is single-input single-output (SISO) or multiple-input multiple-output (MIMO). The default value is SISO. |
| Execution Mode | Configures the function to be either a Direct or Indirect feedthrough function. Enable this control by selecting a parameter from the Parameters list and then selecting Terminal from the Parameter source pull-down list. If you select Configuration Dialog Box from the Parameter source pull-down list, LabVIEW disables this control and calculates the feedthrough behavior automatically. Refer to the Details section for a description of the parameters that determine the feedthrough behavior of this function. This parameter is valid only when you place this function inside a Simulation Loop. |
| Parameters | Lists all the parameters associated with this function. Select a parameter from this list to configure the parameter. When you select a parameter, the parameter and its associated Parameter source control appear in the Parameter Information section of the configuration dialog box. |
| Preview | Displays a graphical preview, if available, of the function output or configuration. |
| Parameter Information | Contains the parameters you can configure for this function. You must select a parameter from the Parameters list to make that parameter and its associated Parameter source control visible in the Parameter Information section of the configuration dialog box. |
| Parameter source | Specifies whether you configure this parameter using the Configuration Dialog Box or a Terminal on the simulation diagram. The default value is Configuration Dialog Box. If you select Terminal, LabVIEW displays an input for that parameter on the simulation diagram, and you can wire values to that input to configure this function programmatically. If you select Configuration Dialog Box, LabVIEW removes that input from the simulation diagram. You then must set the value for this parameter inside the configuration dialog box. |
| Load | Loads model information from a data file. |
| Save | Saves model information to a data file. This file is compatible with the LabVIEW Control Design Toolkit. |
| Copy | Copies the current model definition to the clipboard. From the clipboard, you can paste the model on the block diagram or into another configuration dialog box of the same model form. |
| Paste | Pastes model information from the clipboard to the configuration dialog box. |
| sample period (sec) | Specifies the length of the discrete time step, in seconds, of this function. The default value is –1. If you enter a value of –1, this function inherits the discrete time step you specify for the simulation diagram. Otherwise, the value of sample period (sec) must be a multiple of the discrete time step you specify for the simulation diagram. This parameter is valid only when you place this function inside a Simulation Loop. |
| sample skew (sec) | Specifies the length of time by which you want to delay the execution of this function. The default value is 0. The value of this parameter must satisfy the following relationship: 0 ≤ sample skew (sec) ≤ sample period (sec) This parameter is valid only when you place this function inside a Simulation Loop. |
| Zeros-Poles-Gain | Specifies the zero-pole-gain model.
|
Block Diagram Inputs
| Parameter | Description |
|---|---|
| sample period (sec) | Specifies the length of the discrete time step, in seconds, of this function. The default value is –1. If you enter a value of –1, this function inherits the discrete time step you specify for the simulation diagram. Otherwise, the value of sample period (sec) must be a multiple of the discrete time step you specify for the simulation diagram. This parameter is valid only when you place this function inside a Simulation Loop. |
| sample skew (sec) | Specifies the length of time by which you want to delay the execution of this function. The default value is 0. The value of this parameter must satisfy the following relationship: 0 ≤ sample skew (sec) ≤ sample period (sec) This parameter is valid only when you place this function inside a Simulation Loop. |
| input | Specifies the input to the function. |
| Zeros-Poles-Gain | Specifies a zero-pole-gain model. This input accepts either a block diagram constant or a model you created using the LabVIEW Control Design Toolkit. |
Block Diagram Outputs
| Parameter | Description |
|---|---|
| output | Returns the output of the function. |
Discrete Zero-Pole-Gain Details
For SISO models, this function uses the following equation to calculate the output:
For MIMO models, this function calculates the output as H = [Hij].
| where | k is the gain |
| Z[m] is the array of zeros | |
| P[n] is the array of poles | |
| m is the order of the numerator | |
| n is the order of the denominator | |
| z is the z-transform variable | |
| i is the index number of the input | |
| j is the index number of the output |
The function is based on the Discrete Transfer Function, which is represented in zero-pole-gain notation.
Feedthrough Behavior
The values you specify for the Zeros and Poles subparameters determine the feedthrough behavior of this function. Given Z as the Zeros subparameter and P as the Poles subparameter:
- If the order of Z = the order of P, the function has direct feedthrough behavior.
- If the order of Z < the order of P, the input input has indirect feedthrough to the output output. All other input/output pairs have direct feedthrough behavior.
- If the order of Z > the order of P, LabVIEW returns an error.
When you use the configuration dialog box to configure Z and P, LabVIEW verifies that the feedthrough behavior is correct. For example, if you set the Execution Mode parameter to Indirect, and you set the order of Z equal to the order of P, LabVIEW changes the Execution Mode parameter to Direct.
If you define the zero-pole-gain equation programmatically, LabVIEW does not adjust the feedthrough behavior for you. You must ensure that you specify the proper feedthrough behavior for the orders of Z and P you specify.
Example
Refer to the discrete zero-pole-gain VI in the labview\examples\simulation\Getting Started\Discrete Linear directory for an example of using the Switch VI.