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Owning Palette: Parametric Model Estimation VIs
Requires: System Identification Toolkit
Estimates a discrete or continuous transfer function model for a SISO unknown system. For discrete models, this VI supports the direct, indirect, and joint inputoutput identification methods.
Dialog Box Options 
Block Diagram Inputs 
Block Diagram Outputs 
Parameter  Description 

Signals  Displays the signals used to estimate the system, including the stimulus signal, reference signal, response signal, and estimated response signal. 
Signal Selection  Specifies the signal you want to preview. Contains the following options:

Data type  Specifies the data type for the input signal(s). Contains the following options:

Model type  Specifies the type of model to estimate. Contains the following options:

Signal type  Specifies the type of the input signals. This option is available only when you set Model type to Continuous. Contains the following options:

Settings  Specifies whether the dynamic system contains delay and whether stimulus signal and response signal contain initial condition parts. This option is available only when you set Model type to Continuous and set Signal type to Step response. Contains the following options:

Numerator order  Specifies the order of the numerator of the system model. When you set Model type to Continuous and set Signal type to Step response, this VI sets the value of Numerator order to Denominator order – 1. In this case, you cannot change the value of Numerator order. 
Denominator order  Specifies the order of the denominator of the system model. When you set Model type to Continuous and set Signal type to Step response, the value of Denominator order must be 1 or 2. 
Delay initial guess  Specifies the initial guess of the system delay in seconds. The default is NaN, which means no delay exists in this transfer function. This option is available only when you set Model type to Continuous and set Signal type to General. 
Estimation method  Specifies the estimation method to use for discrete systems. Contains the following options:

Controller numerator  Specifies the numerator coefficients of the discrete, linear controller. This option is available only when you set Model type to Discrete and set Estimation method to Indirect. 
Controller denominator  Specifies the denominator coefficients of the discrete, linear controller. This option is available only when you set Model type to Discrete and set Estimation method to Indirect. 
Controller structure  Specifies the controller position in the feedback loop. If the controller is set before the dynamic system, select Feedforwardpath. If the controller is set after the output, select Feedbackpath. This option is available only when you set Model type to Discrete and set Estimation method to Indirect. 
ZeroPole cancellation tolerance  Determines zeropole cancellations. If the difference between the location of a pole and a zero is within the tolerance, this VI removes the zeropole pair. This option is available only when you set Model type to Discrete and set Estimation method to Indirect. 
System Diagram  Displays the system diagram of the closedloop system. 
Estimated Model  Displays the mathematical equation and sampling rate of the estimated transfer function model. 
Parameter  Description 

stimulus signal  Specifies the input waveform or array of a stimulus signal. 
reference signal  Specifies the input waveform or array of a reference signal. 
response signal  Specifies the input waveform or array of a response signal. 
sampling rate  Specifies the sampling frequency in hertz. For discrete models, sampling rate (Hz) is the system sampling rate. For continuous models, sampling rate is used to convert the continuous model to a discrete model before simulating the output. 
error in (no error)  Describes error conditions that occur before this node runs. 
Parameter  Description  

system model out  system model out returns information about the model structure, nominal or estimated parameters, identification result, and so on. Use the Model Management VIs to retrieve the information system model out contains.
 
coefficients  Returns the coefficients of the transfer function (TF) model. Contains the following elements:
 
continuous delay  Returns the estimated delay of the continuous system in seconds.  
error out  Contains error information. This output provides standard error out functionality. 
This Express VI operates similarly to the following VIs and functions:
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