| Version 7.1 (R2008a) Simulink® Software Release Notes | |
This table summarizes what's new in V7.1 (R2008a):
| New Features and Changes | Version Compatibility Considerations | Fixed Bugs and Known Problems | Related Documentation at Web Site |
|---|---|---|---|
| Yes Details below | Yes—Details labeled as Compatibility Considerations, below. See also Summary. | Bug
Reports Includes fixes | Printable Release Notes: |
New features and changes introduced in this version are organized by these topics:
Improved Rapid Accelerator sim-command performance when running long simulations of small models on Microsoft® Windows® platforms.
Long Rapid Accelerator mode simulations of small models invoked by the sim command under the Microsoft Windows operating system now run faster.
A second zero crossing algorithm that is especially useful in systems exhibiting strong chattering behavior has been added for use with variable step solvers.
The new algorithm is selected by choosing Adaptive from the Zero crossing location algorithm option in the Solver pane of the Configuration Parameter dialog. The default algorithm is Non-Adaptive, which is the algorithm used prior to this release.
For more information, see Zero Crossing Algorithms.
In previous releases, changing a referenced model that executed in Accelerator mode or was used for code generation triggered rebuilding every model that directly or indirectly referenced the changed model. The rebuilding occurred even if the change to the referenced model had no effect on its interface to its parent(s).
In R2008a, changing a referenced model that executes in Accelerator mode or is used for code generation triggers rebuilding a parent model only when the change directly affects the referenced model's interface to the parent model. This behavior eliminates unnecessary code regeneration, which can significantly reduce the time needed to update a diagram.
The faster diagram update has no effect on simulation behavior or performance, but may change the messages that appear in the MATLAB® Command Window. See Referencing a Model for information about model referencing.
The Configuration Parameters > Model Referencing > Pass scalar root inputs by value option is Off by default, indicating that scalar root inputs are passed by reference. In previous releases, setting the option to On affected both simulation and generated code, and caused scalar root inputs to be passed by value. In R2008a, the option has no effect on simulation: scalar root inputs are now always passed by reference, regardless of the setting of Pass scalar root inputs by value. The effect of the option on code generation is the same as in previous releases. See Pass scalar root inputs by value for Real-Time Workshop for more information.
In previous releases, Microsoft Windows imposed a limit on the number of models that could be referenced in Accelerator mode in a model hierarchy. This limitation is removed in R2008a. Under Microsoft Windows, as on all other platforms, the number of referenced models that can appear in a model hierarchy is effectively unlimited. See Referencing a Model for information about model referencing.
Embedded MATLAB™ Function blocks now support nontunable MATLAB structure parameters. For more information, see Working with Non-Tunable Structure Parameters in Embedded MATLAB™ Function Blocks.
You can navigate between a line of generated code and its corresponding line of source code in Embedded MATLAB Function blocks. For more information, see Using Traceability in Embedded MATLAB™ Function Blocks.
When you define data of fixed-point type in Embedded MATLAB Function blocks, you must specify the scaling explicitly in the General pane of the Data properties dialog box. For example, you cannot enter an incomplete specification such as fixdt(1,16) in the Type field. If you do not specify scaling explicitly, you will see an error message when you try to simulate your model.
To ensure that the data type definition is valid for fixed-point data, perform one of these steps in the General pane of the Data properties dialog box:
Use a predefined option in the Type drop-down menu.
Use the Data Type Assistant to specify the Mode as fixed-point.
Compatibility Considerations. Previously, you could omit scaling in data type definitions for fixed-point data. Such data types were treated as integers with the specified sign and word length. This behavior has changed. Embedded MATLAB Function blocks created in earlier versions may now generate errors if they contain fixed-point data with no scaling specified.
When you export signals to a workspace in Array format from more than one outport, none of the signals can be a matrix signal. In previous releases, violating this rule did not always cause an error, but the matrix data was not exported correctly. In R2008a, violating the rule always causes an error, and no data export occurs. See Array for complete information about Array format requirements.
When exporting data to a workspace in Array format from multiple outports, use a Reshape block to convert any matrix signal to a one-dimensional (1-D) array. This restriction applies only to Array format. If you specify either Structure or Structure with time format, you can export matrix signals to a workspace from multiple outports without first converting the signals to vectors.
Compatibility Considerations. The more stringent error checking in R2008a can cause models that export data in Array format from multiple outports to generate errors rather than silently exporting matrix data incorrectly. To eliminate such errors, use a Reshape block to convert any matrix signal to a vector, or switch to Structure or Structure with time format. See Exporting Data to the MATLAB® Workspace for information about data export.
The Simulink® Bus Editor has been reimplemented to provide a GUI interface similar to that of the Model Explorer, and to provide several new capabilities, including importing/exporting data from MAT-files and M-files, defining bus objects and elements with the Data Type Assistant, and creating and viewing bus hierarchies (nested bus objects). See Using the Bus Editor for details.
In previous releases, changing the value of any variable or parameter during simulation took effect immediately. In R2008a, only changes to tunable variables and parameters take effect immediately. Other changes have no effect until the next simulation begins. This modification causes simulation behavior to match generated code behavior when the values of nontunable variables and parameters change, and it improves efficiency by eliminating unnecessary re-evaluation. For information about parameter tuning, see Tunable Parameters and Changing the Values of Block Parameters During Simulation.
Compatibility Considerations. In R2008a, simulation behavior will differ if the behavior in a previous release depended on changing any nontunable variable or parameter during simulation. To regain the previous behavior, define as tunable any nontunable variable or parameter that you want to change during simulation for the purpose of affecting simulation immediately.
Illegal rate transitions between a block and a triggered subsystems or function call subsystems are now detected when the block is connected to a Unit Delay or Zero Hold block inside a triggered subsystem.
Compatibility Considerations. In this release, Simulink detects illegal rate transition errors when the block sample time is different from the triggered subsystem sample time in those models where the block is connected to a Unit Delay or Zero Hold block inside the triggered subsystem.
In R2008a, when you define a fixed-point data type in a Simulink model, you must explicitly specify the scaling unless the block supports either integer scaling mode or best-precision scaling mode. If a block supports neither of these modes, you cannot define an incomplete fixed-point data type like fixdt(1,16), which specifies no scaling. See Specifying a Fixed-Point Data Type and Showing Fixed-Point Details for information about defining fixed-point data types.
Compatibility Considerations. In previous releases, you could define a fixed-point data type that specified no scaling in a block that supported neither integer scaling mode nor best-precision scaling mode. The Simulink software posted no warning, and treated fixed-point data type as an integer data type with the specified word length. For example, fixdt(1,16) was treated as fixdt(1,16,0).
In R2008a, a fixed-point data type definition that specifies no scaling generates an error unless the block supports either integer scaling mode or best-precision scaling mode. If such an error occurs when you compile a model from an earlier Simulink version, redefine the incomplete fixed-point data type to be an integer type if nothing more is needed, or to be scaled appropriately for its value range.
The Data Type Assistant can now display the status and details of fixed-point data types. See Specifying a Fixed-Point Data Type and Showing Fixed-Point Details for more information.
When you log time, states, final states, and signals on a 64-bit platform, you can now save more simulation data in the MATLAB base workspace than was previously possible.
When you log data using the Structure, Structure with time, or Timeseries format, you can now save up to 2^48-1 bytes in each field that contains logged data.
When you log data using Array format, you can now save up to 2^48-1 bytes in each array that contains logged data.
Previously the limit was 2^31-1 bytes in each field or array containing logged data. See Logging Signals and Data Import/Export Pane for information about logging data.
Previous releases did not provide range checking for complex numbers, and attempting it generated an error. In R2008a, you can specify a minimum and/or maximum value for a complex number wherever range checking is available and a complex number is a legal value.
The specified minimum and maximum values apply separately to the real part and to the imaginary part of the complex number. If the value of either part of the number is less than the minimum, or greater than the maximum, the complex number is outside the specified range.
No range checking occurs against any combination of the real and imaginary parts, such as (sqrt(a^2+b^2)). See Checking Parameter Values and Checking Signal Ranges for information about range checking.
In this release, Simulink never automatically inserts a Rate Transition block into a virtual bus, even if Automatically handle rate transfer is selected. Instead, an error is displayed indicating that a Rate Transition block must be manually inserted.
Compatibility Considerations. Some models that worked in previous releases, but were dependent on automatic Rate Transition block insertion, will now report an error and will no longer run. An error will be reported if all of these apply:
The Automatically handle rate transfer option is enabled
The model is multirate
The model has a virtual bus, all of the elements on the bus have the same data type, and the sample time changes
A bus selector block is not present on the virtual bus at a point after the sample time changes
The only way to address the rate transition problem is to insert a rate transition block
In models with asynchronous function calls, some virtual blocks now correctly assign generic sample times instead of triggered sample times.
Compatibility Considerations. The CompiledSampleTime parameter now reports the compiled sample time as generic sample time (that is, [-1, -inf]) rather than triggered sample time ([-1,-1]) for virtual blocks for which all of the flowing is true:
The virtual block is downstream from an asynchronous source
The virtual block is not inside a triggered subsystem
The virtual block had a triggered ([-1,-1]) sample time in previous releases
The simulation results, code generation, and sample time colors are not affected by this change.
In R2008a, the Simulink Editor by default graphically indicates signals that must resolve to signal objects. For any labeled signal whose Signal name must resolve to signal object property is enabled, a signal resolution icon appears to the left of the signal name. The icon looks like this:
A signal resolution icon indicates only that a signal's Signal name must resolve to signal object property is enabled. The icon does not indicate whether the signal is actually resolved, and does not appear on a signal that is implicitly resolved without its Signal name must resolve to signal object property being enabled. See Signal Resolution Indicators for more information.
New Autosave option automatically creates a backup copy of models before updating or simulating. If you open or load a model which has a more recent autosave copy available, a dialog appears where you can choose to overwrite the original model file with the autosave copy.
You can set the Autosave option in the Simulink Preferences Window. See Autosave in the Simulink Graphical User Interface documentation.
New option to notify when loading a model saved in a previous version of Simulink software.
You can set this option in the Simulink Preferences Window. See Simulink® Preferences Window: Main Pane in the Simulink Graphical User Interface documentation.
Enhanced file dependency analysis now also detects:
TLC files required by S-functions.
.fig files created by GUIDE.
Files referenced by common data loading functions. File names passed to xlsread, importdata, dlmread, csvread, wk1read, and textread are now identified, in addition to the existing capability for load, fopen and imread.
See Dependency Analysis in the Using Simulink documentation.
The Discrete FIR Filter block in the Discrete library is new for this release. This block independently filters each channel of the input signal with the specified digital FIR filter. The Discrete FIR Filter block replaces the Weighted Moving Average block.
Compatibility Considerations. You should replace Weighted Moving Average blocks in your existing models with the Discrete FIR Filter block. To do this, run the slupdate command on your models.
Support for Rate Transition blocks has been enhanced in the following ways:
Rate Transition block output port sample time now can be specified as a multiple of input port sample time, using the new Rate Transition block parameters Output port sample time options and Sample time multiple (>0). See the Rate Transition block documentation in the Simulink® Reference for more information.
In previous releases, auto-insertion of Rate Transition blocks was selected for a model using the option Automatically handle data transfers between tasks on the Solver pane of the Configuration Parameters dialog box. When selected, auto-insertion always ensured data transfer determinism for periodic tasks.
This release allows you to control the level of data transfer determinism when auto-insertion of Rate Transition blocks is selected for your model. The Solver pane option for selecting auto-insertion has been renamed to Automatically handle rate transition for data transfer. Selecting auto-insertion now enables a new option, Deterministic data transfer. Selecting Never (minimum delay) or Whenever possible for this option can provide reduced latency for models that do not require determinism. See the Solver Pane section in the Simulink® Graphical User Interface documentation for more information.
Auto-insertion of Rate Transition blocks is now supported for additional rate transitions, such as sample times with nonzero offset, and between non-integer-multiple sample times.
The Lookup Table (n-D) block now supports all data types, complex table data, and nonscalar inputs. See the Lookup Table (n-D) block documentation in the Simulink® Reference for more information.
The Sum block dialog box displays a new parameter for specifying the data type of its accumulator. See the Sum block documentation for more information.
A new version of the Simulink Library browser has the following enhancements:
Now available on all platforms supported by Simulink software.
Improved performance for browsing and searching of libraries, by allowing these operations to proceed without actually loading the libraries.
Enhanced search finds all blocks and displays search results in a separate tab.
New option to display library blocks in a compact grid layout that conserves screen space.
New unified Simulink Preferences window for configuring default settings. The new Preferences window allows you to configure file change notifications, autosave options, fonts, display options, and model configuration defaults.
See Simulink® Preferences Window: Main Pane in the Simulink Graphical User Interface documentation.
In R2008a, the Model Advisor tool is enhanced with improved GUI navigation, check analysis, and reports including:
Reset option that reverts the status of all checks to Not Run while keeping the current check selection.
Model Advisor Result Explorer to make changes to your model.
Input Parameters to provide inputs to checks.
Check results reported in the same order as the Model Advisor tree.
The ability to generate reports for any folder.
Timestamps in reports indicating when checks run at different times.
See Consulting the Model Advisor in the Simulink User's Guide.
Enhanced controls in the Solver pane of the Configuration Parameters dialog. The Solver pane of the Configuration Parameters dialog has been changed as follows:
The Solver diagnostic controls pane has been removed and two new panes have been added (Tasking and sample time options, and Zero crossing options)
The Automatically handle data transfers between tasks control has been moved to the Tasking and sample time options pane, and has been renamed Automatically handle rate transition for data transfer
The Higher priority value indicates higher task priority control has been moved to the Tasking and sample time options pane
The Number of consecutive min step size violations allowed control has been moved to the Solver options pane, and has been renamed Consecutive min step size violations allowed
The States shape preservation control has been added to the Solver options pane
The Consecutive zero crossings relative tolerance control has been moved to the Zero crossing options pane
The Number of consecutive zero crossings allowed control has been moved to the Zero crossing options pane
The Zero crossing control control has been moved to the Zero crossing options pane
The Zero crossing location algorithm control has been added to the Zero crossing options pane
The Zero crossing location threshold control has been added to the Zero crossing options pane
Options that in previous releases were only visible when enabled are now always visible. They are grayed when not enabled.
For more information on the Configuration parameters solver pane, see Solver Pane.
Compatibility Considerations. The Solver pane of the Configuration Parameter dialog has been restructured, and many parameters have moved or been renamed. Please refer to the list of changes above for information on specific parameters.
R2008a introduces "What's This?" context-sensitive help for parameters that appear in the Simulink Configuration Parameters dialog. This feature provides quick access to a detailed description of the parameters, saving you the time it would take to find the information in the Help browser.
To use the "What's This?" help, do the following:
Place your cursor over the label of a parameter.
Right-click. A What's This? context menu appears.
For example, the following figure shows the What's This? context menu appearing after a right-click on the Start time parameter in the Solver pane.
Click What's This? A context-sensitive help window appears showing a description of the parameter.
New basic version of the Level-2 M-file S-function template msfuntmpl_basic.m simplifies creating Level-2 M-file S-functions. See Writing Level-2 M-File S-Functions in Writing S-Functions for more information.
MATLAB V7.6 (R2008a) on Linus Torvalds' Linux® platforms is now built with a compiler that utilizes glibc version 2.3.6. To work with MATLAB V7.6 (R2008a), MEX-file S-functions compiled on a Linux® platform must be rebuilt.
| Simulink® Release Notes | Version 7.0 (R2007b) Simulink® Software | |
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