CD Step Response VI

Control Design VI and Function

previous page
CD Step Response VI

Owning Palette: Time Response VIs

Installed With: Control Design and Simulation Module

Calculates the output of the system when a step input excites it. This VI assumes the initial states of the system to be zero. The data type you wire to the State-Space Model input determines the polymorphic instance to use.

Note  In the state-space version of the CD Step Response VI, the State Trajectory Graph is not available when the model contains transport delays. You can reduce the nonzero delay entries in the transport delay matrix with the CD Distribute Delay VI. However, distributing the transport delay does not accurately reflect the effect of the delay in the states. Therefore, when transport delays are present in state-space models, the CD Step Response VI eliminates the state trajectories.

Details  

Use the pull-down menu to select an instance of this VI.

 Place on the block diagram  Find on the Functions palette

Step Response (State-Space)

States Graph Ref is a reference to the State Trajectories graph. States Graph Ref configures the x-scale, y-scale, and legend properties. If you want to use the default settings or customize the settings for these properties, do not wire a value to this input.
Response Graph Ref is a reference to the Step Response graph. Response Graph Ref configures the x-scale, y-scale, and legend properties. If you want to use the default settings or customize the settings for these properties, do not wire a value to this input.
State-Space Model contains a mathematical representation of and information about the system of which this VI calculates step response.
Time Range contains information about the initial time, final time, and time step.
t0 is the initial time in seconds in the Step Response graph. The default is –1.
dt is the constant interval between successive values in the time vector. The default is –1.
tf is the final time in seconds up to which this VI calculates the step response. The default is –1.
Initial Conditions specifies the initial values of the states or outputs. The default is 0.
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 exception control to treat what is normally an error as no error or to treat a warning as an error. 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.
Response Plots Index specifies the index number of the inputs and outputs of the system.
Input # is the index number of the specific input to the system. This VI displays the response to this input on the Step Response graph. The index is zero-based.
Output # is the index number of the specific output of the system that this VI displays on the Step Response graph. The index is zero-based.
State Plots Index specifies the index number of the inputs and outputs of the system.
Input # is the index number of the specific input to the system. This VI displays the response to this input on the Step Response graph. The index is zero-based.
State # is the index number of the specific state of the system that this VI displays in the Step Response graph. The index is zero-based.
Step Response Graph displays a graph that shows the forced response of the system when the forcing function is a step. For MIMO systems, this VI determines the step response by applying a step on one input at a time and letting other inputs to the system be zero.
State Trajectory Graph displays an XY graph that shows the value of each state as a function of time. For MIMO systems, this VI calculates the states for each input at a time, where one input is the impulse and all the other inputs to the system are zero.
Step Response Data returns information about the step response. To access the Step Response Data, use the CD Get Time Response Data VI.
Time is the uniformly-spaced time vector against which this VI plots the step response and the state trajectories.
Outputs Data returns data about the time response of the outputs to the inputs. Refer to the Details section for more information about the Outputs Data.
States Data returns data about the time response of the states to the inputs. For transfer function and zero-pole-gain models, this array is empty. Refer to the Details section for more information about the States Data.
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.

Step Response (Transfer Function)

Response Graph Ref is a reference to the Step Response graph. Response Graph Ref configures the x-scale, y-scale, and legend properties. If you want to use the default settings or customize the settings for these properties, do not wire a value to this input.
Transfer Function Model contains a mathematical representation of and information about the system of which this VI calculates step response.
Time Range contains information about the initial time, final time, and time step.
t0 is the initial time in seconds in the Step Response graph. The default is –1.
dt is the constant interval between successive values in the time vector. The default is –1.
tf is the final time in seconds up to which this VI calculates the step response. The default is –1.
Initial Conditions specifies the initial values of the states or outputs. The default is 0.
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 exception control to treat what is normally an error as no error or to treat a warning as an error. 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.
Response Plots Index specifies the index number of the inputs and outputs of the system.
Input # is the index number of the specific input to the system. This VI displays the response to this input on the Step Response graph. The index is zero-based.
Output # is the index number of the specific output of the system that this VI displays on the Step Response graph. The index is zero-based.
Step Response Graph displays a graph that shows the forced response of the system when the forcing function is a step. For MIMO systems, this VI determines the step response by applying a step on one input at a time and letting other inputs to the system be zero.
Step Response Data returns information about the step response. To access the Step Response Data, use the CD Get Time Response Data VI.
Time is the uniformly-spaced time vector against which this VI plots the step response and the state trajectories.
Outputs Data returns data about the time response of the outputs to the inputs. Refer to the Details section for more information about the Outputs Data.
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.

Step Response (Zero-Pole-Gain)

Response Graph Ref is a reference to the Step Response graph. Response Graph Ref configures the x-scale, y-scale, and legend properties. If you want to use the default settings or customize the settings for these properties, do not wire a value to this input.
Zero-Pole-Gain Model contains a mathematical representation of and information about the system of which this VI calculates step response.
Time Range contains information about the initial time, final time, and time step.
t0 is the initial time in seconds in the Step Response graph. The default is –1.
dt is the constant interval between successive values in the time vector. The default is –1.
tf is the final time in seconds up to which this VI calculates the step response. The default is –1.
Initial Conditions specifies the initial values of the states or outputs. The default is 0.
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 exception control to treat what is normally an error as no error or to treat a warning as an error. 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.
Response Plots Index specifies the index number of the inputs and outputs of the system.
Input # is the index number of the specific input to the system. This VI displays the response to this input on the Step Response graph. The index is zero-based.
Output # is the index number of the specific output of the system that this VI displays on the Step Response graph. The index is zero-based.
Impulse Response Graph displays an XY graph that shows the forced response of the system when the forcing function is an impulse. For MIMO systems, this VI determines the impulse response by applying an impulse on one input at a time and letting other inputs to the system equal zero.
Step Response Data returns information about the step response. To access the Step Response Data, use the CD Get Time Response Data VI.
Time is the uniformly-spaced time vector against which this VI plots the step response and the state trajectories.
Outputs Data returns data about the time response of the outputs to the inputs. Refer to the Details section for more information about the Outputs Data.
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.

CD Step Response Details

This VI supports input and output delays. This VI ignores transport delay information. Refer to the LabVIEW Control Design User Manual for more information about delays.

previous page start