Upgrading from an Earlier Release :: Simulink 6.0 Release Notes (Simulink® Release Notes)

Simulink® Release Notes

Upgrading from an Earlier Release

Note If you are upgrading from Version 5.0 or earlier, then you should see Upgrading from an Earlier Release in the Simulink 5.0.1 Release Notes.

Changes in MATLAB Data Type Conversions

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.

Signal Object Resolution Changes

In previous releases, Simulink attempted to resolve every named signal to a Simulink.Signal object of the same name in the MATLAB workspace. In this release, Simulink 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 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 displays a warning. You can also specify that Simulink 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.

Loading Models Containing Non-ASCII Characters

Release 14 of MATLAB introduces Unicode support. This enhancement allows MATLAB and Simulink to support character sets from different encoding systems. However, this change causes Simulink 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 checks the characters in the model against the current encoding setting of MATLAB. If they are incompatible, Simulink 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.

Major Bug Fixes Change in Sample Time Behavior of Unary Minus Block