This topic lists new features in the LabVIEW 2012 Control Design and Simulation Module. Refer to the LabVIEW 2012 Features and Changes topic for information about new features in LabVIEW 2012.

Note Refer to the readme_ControlandSim.html file, located in the labview\readme directory, for a complete list of new features and changes, information about upgrade and compatibility issues specific to different versions of the Control Design and Simulation Module, and information about known issues with the LabVIEW 2011 Control Design and Simulation Module. |

Use the SISO Controller function or CD Interactive Control Design VI to interactively design and analyze controllers for continuous, single-input single-output (SISO) dynamic systems. These nodes provide access to an interface that helps you perform the control design process. The SISO Controller function also implements controllers in a simulation diagram, so you can close the loop between the setpoint and the plant with this function.

Use the following features to collect simulation data, such as signal values, on the block diagram:

- Access Model Hierarchy function—Collects signals continuously, a point at a time, at run time. This function works similarly to a probe.
- Output Node of the Control & Simulation Loop—Collects and stores the value of a signal over the duration of the simulation for later access. This feature is similar to the Collector function.

These features are useful for accessing signals in other VIs or subsystems. For example, instead of passing values through the connector panes of subsystems to the block diagram where you want the value, you can use these features to collect values from any level in the hierarchy of a simulation diagram.

The Control & Simulation Loop provides the following new ordinary differential equation (ODE) and differential algebraic equation (DAE) solvers:

- Gear's Method
- Radau 5
- Radau 9
- Radau 13
- Radau [Variable Order]
- SDIRK 4

Use the getmodelparam, setmodelparam, and setmodelparam_eval LabVIEW MathScript functions to read and write parameters of Simulation functions and subsystems from a MathScript Node or the **LabVIEW MathScript Window**. These functions are useful for setting parameters with values computed in a script. You can use these functions to access parameters in the same VI or in another VI.

The Callback API category of External Solver Interface (ESI) functions includes the new InterpolateStates function.

The Simulation palette contains the following subpalettes:

- Model Hierarchy—Contains functions that allow you to configure model parameters and collect signals in a simulation.
- Controllers—Contains functions that allow you to design and implement a controller based on the linear model of the system.

The Control Design palette contains the Interactive Design subpalette and its CD Interactive Control Design VI, which allows you to interactively design and analyze a controller before you generate the controller for use in a dynamic system.

The LabVIEW 2012 Control Design and Simulation Module includes the following enhancements to VIs and functions:

- In the Control Design and Simulation Module 2011 and earlier, the Discrete Unit Delay function delays the input by a discrete time step of the size you specify. In the Control Design and Simulation Module 2012, this function is renamed Discrete Delay, and the function delays the input by the number of discrete time steps you specify.
- The CD Continuous Algebraic Riccati Equation and CD Discrete Algebraic Riccati Equation VIs include the following enhancements:
- These VIs include a new
**algorithm**input that specifies the type of algorithm to use to solve the Riccati equation: Schur, Eigenvalues, QZ, or an automatic method of selecting an algorithm and solving the equation. - In the Control Design and Simulation Module 2011 and earlier, these VIs return the relative residual of the Riccati solution in the
**Relative Residuals**output. In the Control Design and Simulation Module 2012, these VIs return the absolute residual, and the output is renamed**Residual**.

- These VIs include a new
- The CD Nyquist VI contains a
**Separate Contour?**input, which, if TRUE, produces two plots: one that represents the positive frequencies and one for negative frequencies. Otherwise, this VI produces one plot for both the positive and negative frequencies. Separating the plots allows you to verify the direction of negative frequencies. - The CD Sensitivity Functions VI include the following enhancements:
- The
**Noise Sensitivity (CS)**output is renamed**Controller Noise Sensitivity (CS)**. - These VIs include a new
**Output Noise Sensitivity (-T)**output, which returns the model equivalent to the sensitivity of noise to the output of the system.

- The
- The CD All Margins and CD Gain and Phase Margin VIs include a
**Delay Margins**and**Delay Margin**output, respectively, that returns information about delay margins in the system. - In the Control Design and Simulation Module 2011 and earlier, the margins Control Design MathScript RT Module function returns only the gain margin frequencies of the input system model if you request zero or one output from the function. In the Control Design and Simulation Module 2012, margins returns a structure whose elements describe the gain, phase, and delay margins of the model.

The LabVIEW 2012 Control Design and Simulation Module includes the following enhancements to VIs and functions:

- The Read/Write Model Parameters function is renamed the Access Model Hierarchy function.
- In the Control Design and Simulation Module 2011 and earlier, each instance of the CD Inverse Model polymorphic VI has an optional input that accepts a model. In the Control Design and Simulation Module 2012, this input is required, and the inputs are renamed
**Model In**.