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| R2012a Documentation → Simulink | |
Learn more about Simulink |
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| Contents | Index |
This table summarizes what's new in V6.0 (R14):
| New Features and Changes | Version Compatibility Considerations | Fixed Bugs and Known Problems |
|---|---|---|
| Yes Details below | Yes—Details labeled as Compatibility Considerations, below. See also Summary. | Fixed Bugs |
New features and changes introduced in this version are organized by these topics:
The Model Explorer is a new tool that lets you quickly navigate, view, create, configure, search, and modify all data and properties of a Simulink model or Stateflow chart. See The Model Explorer: Overview in the online Simulink help for more information.
This release introduces configuration sets. A configuration set is a named set of values for simulation parameters, such as solver type and simulation start or stop time. Every new model is created with a configuration set that is initialized from a global default configuration set. You can create additional configuration sets for a given model and designate any of them as the active set with the click of a mouse button. See Manage a Configuration Set in the online Simulink documentation for more information.
This release replaces the Simulation Parameters dialog box with the Configuration Parameters dialog box. The Configuration Parameters dialog box allows you to set a model's active configuration parameters. You can also use the Model Explorer to set the active configuration parameters as well as inactive parameters. See Configuration Parameters Dialog Box for more information.
This release introduces model referencing, a feature that lets a model include other models as modular components. You include other models in a model by using Model blocks to reference the included models. Like subsystems, model referencing allows you to organize large models hierarchically, with Model blocks representing major subsystems. However, model referencing has significant advantages over subsystems in many applications. The advantages include:
Modular development
You can develop the referenced model independently from the models in which it is used.
Inclusion by reference
You can reference a model multiple times in another model without having to make redundant copies. Multiple models can also reference the same model.
Incremental loading
The referenced model is not loaded until it is needed, speeding up model loading.
Incremental code generation
Simulink and Real-Time Workshop products create binaries to be used in simulations and standalone applications to compute the outputs of the included blocks. Code generation occurs only for models that have changed.
See Referencing a Model in the online Simulink documentation for more information. For a demonstration of a way to automate conversion of an existing model's subsystems to model references, execute mdlref_conversion at the MATLAB Command Line. For a summary of limitations on the use of model referencing in this release, see Model Referencing Limitations.
In this release, Simulink software provides each model with its own workspace for storing data. Models can access data in their own workspaces as well as data in models that reference them and in the base (i.e., MATLAB) workspace. Model workspaces allow you to create data for one model without fear of inadvertently altering another model's data. See Using Model Workspaces for more information.
This release includes a new fixed-step solver named ode14x. This is an implicit, extrapolating fixed-step solver whose extrapolation order and number of Newton's method iterations can be specified via Simulink configuration parameters. The ode14x solver is faster than Simulink explicit fixed-step solvers for certain types of stiff systems that require a very small step size to avoid unstable solutions.
The Signal and Scope Manager is a new Simulink feature that enables you to globally manage signal generators and viewers. See Signal and Scope Manager in the online Simulink help for more information.
This release introduces the following types of objects for specifying the properties of model signals and parameters (i.e., model data):
Object Class | Purpose |
|---|---|
Specify another name for a data type. | |
Define a custom data type. | |
Define a signal bus. |
See Working with Data Types and Simulink Classes in the Simulink online documentation for more information.
This release also adds the following properties to Simulink.Signal class:
Dimensions
SampleTime
SamplingMode
DataType
Complexity
Simulink software checks the consistency of these properties against the values set on the ports/dwork elements associated with each signal object.
This release includes the following block-related enhancements.
This release introduces the following blocks.
The Signal Conversion block enables you to convert virtual buses to nonvirtual buses, and vice versa.
The Environment Controller block's output depends on whether the model is being used for simulation or code generation.
The Bias block adds a specified bias value to its input and outputs the result.
MATLAB Function (formally called Embedded MATLAB Function) block enables you to include MATLAB code in models from which you intend to generate code, using Real-TimeWorkshop® software.
The Model block allows you to include other models in a model (see Model Referencing).
This release adds fixed-point data capability to many existing Simulink blocks and includes fixed-point blocks previously available only with the Fixed-Point Blockset. To use the fixed-point data capability of these blocks, you must install the Simulink Fixed Point product on your system. See Fixed-Point Data in the online Simulink documentation for more information.
This release of Simulink software can display block outputs as data tips on a block diagram while a simulation is running. This allows you to observe block outputs without having to insert Scope or Display blocks. See Displaying Port Values in the online Simulink documentation for more information.
This release expands the number of blocks with user-specifiable sample times to include most built in Simulink blocks. In previous releases, most builtin blocks inherited their sample times directly or indirectly from the blocks to which they were connected. In this release, most blocks continue to inherit their sample times by default. However, you can override this default setting in most cases to specify a nondefault sample time, using either the block's parameter dialog box or a set_param command. This avoids the need to use Signal Specification blocks to introduce nondefault sample times at specific points in a model.
In previous Simulink releases, the Constant, Initial Condition, Unit Delay, and other blocks write out their initial output values in their mdlStart method. This behavior can cause unexpected block output initialization. For example, if a Constant block in an enabled subsystems feeds an Outport block whose IC is set to [], the Constant value appears even when the enabled subsystem is not enabled.
It is desirable in some cases for a block to write its initial output value in its mdlStart method. For example, discrete integrator block may need to read the value from its external IC port to setting the initial state in mdlInitialize method.
This release addresses these problems by implementing a hand-shaking mechanism for handling block initial output. Under this mechanism, a block only computes its initial output value when it is requested by its downstream block. For example, if a Constant block feeds the external IC port of a Discrete Integrator block, the discrete integrator block's external IC port requests the Constant block to compute its initial output value in its mdlStart method.
In previous releases, Simulink software propagated buses only through virtual blocks, such as subsystems. In this release, Simulink software also propagates buses through the following nonvirtual blocks:
Some of these blocks impose constraints on bus propagation through them. See the documentation for the individual blocks for more information.
This release allows you to create duplicates of Inport blocks in a model. A model can contain any number of duplicates of an original Inport block. The duplicates are graphical representations of the original intended to simplify block diagrams by eliminating unnecessary lines. The duplicate has the same port number, properties, and output as the original. Changing a duplicate's properties changes the original's properties and vice versa. See the Inport block documentation for more information.
Inport and Outport blocks can now optionally display their port number, signal name, or both the number and the name. See the online documentation for the Inport and Outport blocks for more information.
In this release, some blocks that use indices provide the option for indices to start at 0 or 1. The default is one-based indexing to maintain compatibility with previous releases. Blocks that now support zero- or one-based indexing include
This release introduces an application programming interface (API) that enables programmatic access to block data, such as block inputs and outputs, parameters, states, and work vectors, while a simulation is running. You can use this interface to develop MATLAB programs capable of accessing block data while a simulation is running or to access the data from the MATLAB command line. See Accessing Block Data During Simulation for more information.
This release provides a command, signalbuilder, for creating and accessing Signal Builder blocks in a model.
This release includes the following signal-related enhancements.
This release can optionally use indicators on a block diagram to indicate signals that are test points. See Displaying Test Point Indicators in the online documentation for more information.
This release allows you to log signal data during simulation. See Exporting Signal Data Using Signal Logging for more information.
This release revamps the sigmap, siglists and sigregions structures to support signal logging and other signal-related enhancements.
Compatibility Considerations. S-functions created prior to Version 6 (R14). that access the sigmap, siglists and sigregions structures might generate segmentation violations. To avoid this, recompile the S-functions in Version 6 (R14) or subsequent releases.
In this release, when you change a signal label, Simulink software automatically propagates the change to all downstream instances of the label. You do not have to update the diagram as in previous releases.
The new Bus Editor enables you to create and modify bus objects in the Simulink base (MATLAB) workspace. See "Bus Editor" for more information.
This release provides the following enhancements to the handling of rate transitions in models.
The Rate Transition block now determines the type of transition that occurs between the source and destination block (i.e., fast-to-slow or slow-to-fast). Therefore, this release eliminates the transition type option on the block's parameter dialog.
This release introduces an option to insert hidden rate transition blocks automatically between blocks that operate at different rates. This saves you from having to insert rate transition blocks manually in order to avoid illegal rate transitions. The inserted blocks are configured to ensure that data is transferred deterministically and that data integrity is maintained during the transfer. See Automatically handle rate transition for data transfer in the online Simulink documentation for more information.
The Rate Transition Block's parameter dialog box contains a new parameter: Output Port Sample Time. This parameter allows you to specify the output rate to which the input rate is converted. If you do not specify a rate, the Rate Transition block inherits its output rate from the block to which its output is connected.
This releases introduces the following enhancements to execution context propagation.
This release allows you to specify whether to permit execution contexts to be propagated across a conditionally executed subsystem's boundary. See the documentation for the Subsystem block for more information.
This release optionally displays a bar across each input port and output port of a subsystem that does not permit propagation of the subsystem's execution context. To enable this option, select Block Displays->Execution context indicator from the model editor's Format menu.
This release can eliminate some types of algebraic loops involving atomic or enabled subsystems or referenced models. See How Simulink Eliminates Artificial Algebraic Loops in the online Simulink documentation for more information.
This release introduces a new application programming interface (API) for creating custom Simulink blocks based on M code. In contrast to the previous API, designated Level 1, which supported a restricted set of block features, the new API, designated Level 2, supports most standard Simulink block features, including support for matrix signals and nondouble data types. See Writing Level-2 MATLAB S-Functions in the online documentation for more information.
You can now use the mouse to pan around model diagrams that are too large to fit in the model editor's window. To do this, position the mouse over the diagram and hold down the left mouse button and the P or Q key on the keyboard. Moving the mouse now pans the model diagram in the editor window.
Release 14 introduces changes in the way MATLAB handles conversions from double to standard MATLAB nondouble data types (e.g., int8, uint8, etc.) and from one nondouble data type to another.
Previous releases of MATLAB use truncation to convert a floating point value to an integer value, e.g., int8(1.7) = 1. Release 14 uses rounding, e.g., int8(1.7) = 2. See "New Nondouble Mathematics Features" in the Release 14 MATLAB Release Notes for a complete description of the changes in data type conversion algorithms introduced in Release 14.
Such changes could affect the behavior of models that rely on nondouble data type conversions of signals and block parameters. For example, a Gain parameter entered as int8(3.7) ends up as 4 in this release as opposed to 3 in previous releases and this difference could change the simulation results. Therefore, if the simulation results for your model differ in Release 14 from previous releases, you should investigate whether the differences result from the changes in data type conversion algorithms, and, if so, modify your model accordingly.
In previous releases, Simulink software attempted to resolve every named signal to a Simulink.Signal object of the same name in the MATLAB workspace.
In this release, Simulink software lets you specify whether a named signal or discrete state should resolve to a signal object, using the Signal Properties dialog box and the State Properties of blocks that have discrete states, such as the Discrete-Time Integrator. By default, Simulink software attempts to resolve every named signal or state to a signal object regardless of whether the model specifies that the signal or state should resolve to a signal object. If the model does not specify resolution for a signal or state and it does resolve, Simulink software displays a warning. You can also specify that Simulink software attempt to resolve all named signals or states without warning of implicit resolutions (the behavior in previous releases) or that it only resolve signals and states that the model specifies should resolve (explicit resolution).
Explicit signal resolution is the recommended approach for doing signal resolution as it ensures that signals that should be resolved are resolved and signals that should not resolve are not resolved. This release includes a script that facilitates converting models that use implicit signal resolution to use explicit resolution. Enter help disableimplicitsignalresolution at the MATLAB command line for more information.
Release 14 of MATLAB introduces Unicode support. This enhancement allows MATLAB and Simulink products to support character sets from different encoding systems.
This change causes Simulink software to behave differently from previous releases when loading a model containing non-ASCII characters. Previous releases load such models regardless of whether the non-ASCII characters are compatible with the current encoding system used by MATLAB. In Release 14, Simulink software checks the characters in the model against the current encoding setting of MATLAB. If they are incompatible, Simulink software does not load the model. Instead, it displays an error message that prompts you to change to a compatible MATLAB encoding setting, using the slCharacterEncoding command.
Release 14 changes the sample time behavior of the Unary Minus block.
In Release 13, if the sample time of this block's input is continuous, the sample time of the block and its output is fixed in minor time step. This block is fixed in minor step and the output signal is fixed in minor step when the input is a continuos sample time signal. In Release 14, if the input is continuous, the block and output sample time are continuous also.
In this release, the initial output is undefined if the Initial output port specifies [].
In previous releases, if the Initial output parameter of an Outport block in a conditionally executed subsystem specified [] as the initial output, the initial output of this port was the initial output of the block driving the Outport block.
In R14, execution context propagation does not cross conditionally executed subsystem boundaries by default.
In R13 SP1 and DACORE2, execution contexts propagate across conditionally executed subsystem boundaries by default. You need to choose the Propagate execution context across subsystem boundary option in the subsystem's parameter dialog box.
In Release 13, accelerator code generation aborted for the case of a Switch block configured with the Criteria for passing first input set to u2 ~=0, with vector inputs of width greater than the RollThreshold (5). Code generation aborted with the following message:
%exit directive: Real-Time Workshop Fatal in block: "/B_1_28", block type "Switch": No parameters to roll.
This release fixes the problem.
 | Version 6.1 (R14SP1) Simulink Software | Version 5.1 (R13SP1) Simulink Software |  |
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