Simulink® Release Notes

Simulink 5.1 Release Notes

New Features

This section summarizes changes and enhancements introduced in Simulink 5.1. Those features are

"Sample Time Parameters Exposed" (see below)
"Enhanced Debugger" (see below)
Context-Sensitive Data Typing of Tunable Parameters
Conditional Execution Behavior
Function-Call Subsystem Enhancements
External Increment Option Added To For Iterator Block

Sample Time Parameters Exposed

Sample time parameters of most Simulink built-in library blocks have been exposed to the user. That is, the sample time parameter of these blocks has been made accessible via the block's dialog box or set_param. This means that most nonvirtual blocks in the Simulink library have a user settable sample time parameter. Prior to this exposure, these blocks had an internal inherited sample time with the exception of the Constant block, which had a constant (inf) sample time. By providing access to the sample time parameter, you no longer need to use the Signal Specification block to apply a nondefault sample times to these blocks.

Enhanced Debugger

This release includes enhancements to the Simulink debugger that enable you to step through a simulation showing information not visible in previous releases. The enhancements include

An expanded command set that now enables you to step a simulation method by method. Previous releases showed only output methods.
An expanded toolbar that gives you push button access to new debugger commands
A Simulation Loop pane that shows the current state of the simulation at a glance

Note Methods are functions that Simulink uses to solve a model at each time step during the simulation. Blocks are made up of multiple methods. "Block execution" in this documentation is shorthand notation for "block methods execution." Block diagram execution is a multi-step operation that requires execution of the different block methods in all the blocks in a diagram at various points during the process of solving a model at each time step during simulation, as specified by the simulation loop.

These changes allow you to pinpoint problems in your model with greater accuracy. The following sections briefly describe the debugger enhancements. See the Simulink documentation for a detailed description of the new features and their usage.

Enhanced Debugger Commands

This release enhances the following debugger commands:

step

In previous releases, this command advanced the simulation from the current block Outputs method over any intervening methods to the next block Outputs method. In this release, step advances the simulation method by method, or into, over, or out of methods, from the first method executed during the simulation to the last. This allows you to determine the result of executing any model, subsystem, or block method executed during the simulation, including block Outputs, Update, and Derivative methods as well as solver methods.

next

In previous releases, this command advanced the simulation to the first block Outputs method executed during the next time step. In this release, it advances the simulation over the next method to be executed, executing any methods invoked by the next method.

break

In previous releases, this command set a breakpoint at the Outputs method of a specified block. In the current release, it sets a breakpoint at any specified method or on all the methods of a specified block.

bafter

In previous releases, this command set a breakpoint after the Outputs method of a specified block. In this release, it sets a breakpoint after a specified method or after each of the methods of a specified block.

minor

In previous releases, this command enabled or disabled stepping across Outputs methods in minor time steps. In the current release, it enables or disables in minor time steps breakpoints set by block for all methods.

New Debugger Commands

This release introduces the following debugger commands:

elist

Displays the method execution lists for the root system and the nonvirtual subsystems of the model being debugged.

etrace

Causes the debugger to display a message in the MATLAB Command Window every time a method is entered or exited while the simulation is running.

where

Displays the call stack of the method at which the simulation is currently suspended.

Enhanced Debugger Toolbar

The debugger toolbar has been expanded to include buttons for the following versions of the step command: step into, step over, step out, and step top.

Simulation Loop Pane

This release adds a Simulation Loop pane to the debugger GUI that displays by method the point in the simulation loop at which the simulation is currently suspended. The debugger updates the pane after each step, next, or continue command, enabling you to determine at a glance the point to which the command advanced the simulation. The pane also allows you to set breakpoints on simulation loop methods and to navigate to the block at whose method the simulation is currently suspended.

Sorted List Pane

This release renames the Block Execution List pane of the debugger GUI to the Sorted List pane to reflect more accurately what the pane contains. The Sorted List pane displays for the root system and each nonvirtual subsystem of the model being debugged a sorted list of the subsystem's blocks. The sorted lists enable you to determine the block IDs of a model's blocks.

Known Software and Documentation Problems Context-Sensitive Data Typing of Tunable Parameters