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| R2011b Documentation → Stateflow | |
Learn more about Stateflow |
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| Contents | Index |
Actions take place as part of Stateflow chart execution. The action can execute as part of a transition from one state to another, or depending on the activity status of a state. Transitions can contain condition actions and transition actions.
Action language defines the categories of actions you can specify and their associated notations. For example, states can have entry, during, exit, and on event_name actions.
An action can be a function call, an event broadcast, a variable assignment, and so on. For more information on actions and action language, see Using Actions in Stateflow Charts.
Format you can use to access and communicate with an application program from a programming or script environment.
Graphical object that enables you to reuse states and subcharts multiple times in a chart. For more information, see Making States Reusable with Atomic Subcharts.
Graphical object that groups together other graphical objects in your chart. For details about how a box affects chart execution, see Grouping Chart Objects with Boxes.
Link from a model to a chart stored in a Simulink library. A chart in a library can have many chart instances. Updating the chart in the library automatically updates all instances of that chart.
Boolean expression to specify that a transition occurs when the specified expression is true.
Illustrates decision points in the system. A connective junction is a graphical object that simplifies Stateflow chart representations and facilitates generation of efficient code. Connective junctions provide different ways to represent desired system behavior.
See Connective Junctions for more information.
Data objects store numerical values for reference in the Stateflow chart.
See Adding Data for more information on representing data objects.
See Stateflow Debugger.
A state has a decomposition when it consists of one or more substates. A chart that contains at least one state also has decomposition. Rules govern how you can group states in the hierarchy. A superstate has either parallel (AND) or exclusive (OR) decomposition. All substates at a particular level in the hierarchy must have the same decomposition.
Parallel (AND) State Decomposition
Parallel (AND) state decomposition applies when states have dashed borders. This decomposition describes states at that same level in the hierarchy that can be active at the same time. The activity within parallel states is essentially independent.
Exclusive (OR) State Decomposition
Exclusive (OR) state decomposition applies when states have solid borders. This decomposition describes states that are mutually exclusive. Only one state at the same level in the hierarchy can be active at a time.
Primarily used to specify which exclusive (OR) state is to be entered when there is ambiguity among two or more neighboring exclusive (OR) states. For example, default transitions specify which substate of a superstate with exclusive (OR) decomposition the system enters by default in the absence of any other information. Default transitions can also specify that a junction should be entered by default. The default transition object is a transition with a destination but no source object.
See Default Transitions for more information.
Events drive chart execution. All events that affect the chart must be defined. The occurrence of an event causes the status of states in a chart to be evaluated. The broadcast of an event can trigger a transition to occur or an action to execute. Events are broadcast in a top-down manner starting from the event's parent in the hierarchy.
See How Events Work in Stateflow Charts for more information.
Tool to search for objects in Stateflow charts on platforms that do not support the Simulink Find tool. See Stateflow Finder.
Representation of an event-driven system. FSMs are also used to describe reactive systems. In an event-driven or reactive system, the system transitions from one mode or state to another prescribed mode or state, provided that the condition defining the change is true.
Set of decision flow paths that start from a transition segment that, in turn, starts from a state or a default transition segment.
Ordered sequence of transition segments and junctions where each succeeding segment starts on the junction that terminated the previous segment.
Set of decision flow paths that start on the same transition segment.
A chart function whose logic is defined by a flow graph. See Graphical Functions for Reusing Logic Patterns and Iterative Loops.
Hierarchy enables you to organize complex systems by placing states within other higher-level states. A hierarchical design usually reduces the number of transitions and produces neat, more manageable charts. See Stateflow Hierarchy of Objects for more information.
Specifies the destination substate of a transition based on historical information. If a superstate has a history junction, the transition to the destination substate is the substate that was most recently active. The history junction applies only to the level of the hierarchy in which it appears.
See the following sections for more information:
Transition that does not exit the source state. Inner transitions are useful when defined for superstates with exclusive (OR) decomposition. Use of inner transitions can greatly simplify chart layout.
See Inner Transitions and Inner Transition to a History Junction Example for more information.
Link to a chart that is stored in a library model.
Stateflow model that is stored in a Simulink library. You can include charts from a library in your model by copying them. When you copy a chart from a library into your model, you create only a link to the library chart. You can create multiple links to a single chart. Each link is called a chart instance. When you include a chart from a library in your model, you also include its Stateflow machine. Therefore, a Stateflow model that includes links to library charts has multiple Stateflow machines.
When you simulate a model that includes charts from a library model, you include all charts from the library model even if links exist only for some of its models. However, when you generate an embedded or standalone custom target, you include only those charts for which there are links. You can simulate a model that includes links to a library model only when all charts in the library model are free of parse and compile errors.
Collection of all Stateflow blocks defined by a Simulink model. This collection excludes chart instances from library links. If a model includes any library links, it also includes the Stateflow machines defined by the models from which the links originate.
A chart function that works with a subset of the MATLAB programming language. See Using MATLAB Functions in Stateflow Charts for more information.
An industry-standard paradigm for modeling finite-state machines, where output is a function of both inputs and state. See Building Mealy and Moore Charts for more information.
Use to add, remove, and modify data, event, and target objects in the Stateflow hierarchy. See Using the Model Explorer with Stateflow Objects for more information.
An industry-standard paradigm for modeling finite-state machines, where output is a function only of state. See Building Mealy and Moore Charts for more information.
Defines a set of objects and the rules that govern the relationships between those objects. Stateflow chart notation provides a way to communicate the design information in a Stateflow chart.
Stateflow chart notation includes:
A set of graphical objects
A set of nongraphical text-based objects
Defined relationships between those objects
A system with parallelism can have two or more states that can be active at the same time. The activity of parallel states is essentially independent. Parallelism is represented with a parallel (AND) state decomposition.
See State Decomposition for more information.
When you simulate a Simulink model containing Stateflow charts, you generate an S-function (MEX-file) for each Stateflow machine. This generated code is a simulation target.
For more information, see S-Function MEX-Files.
Semantics describe how the notation is interpreted and implemented behind the scenes. A completed Stateflow chart communicates how the system will behave. A chart contains actions associated with transitions and states. The semantics describe in what sequence these actions take place during chart execution.
A chart function that you fill with Simulink blocks and call in the actions of states and transitions. This function provides an efficient model design and improves readability by minimizing the graphical and nongraphical objects required in a model. In a Stateflow chart, this function acts like a function-call subsystem block of a Simulink model.
See Using Simulink Functions in Stateflow Charts for more information.
A state describes a mode of a reactive system. A reactive system has many possible states. States in a chart represent these modes. The activity or inactivity of the states dynamically changes based on transitions among events and conditions.
Every state has hierarchy. In a chart consisting of a single state, the parent of that state is the Stateflow chart itself. A state also has history that applies to its level of hierarchy in the chart. States can have actions that execute in a sequence based upon action type. The action types are entry, during, exit, or on event_name actions.
Masked Simulink model that is equivalent to an empty, untitled Stateflow chart. Use the Stateflow block to include a chart in a Simulink model.
The control behavior modeled by a Stateflow block complements the algorithmic behavior modeled in Simulink block diagrams. By incorporating Stateflow blocks into Simulink models, you can add complex event-driven behavior to Simulink simulations. You create models that represent both data and decision flow by combining Stateflow blocks with the standard Simulink and toolbox block libraries.
A Stateflow chart is a graphical representation of a finite state machine where states and transitions form the basic building blocks of the system. See Stateflow Charts and Simulink Models for more information.
Tool for debugging and animating your Stateflow charts. Each state in the chart simulation is evaluated for overall code coverage. This coverage analysis is done automatically when the target is compiled and built with the debug options. The Debugger can also be used to perform dynamic checking. The Debugger operates on the Stateflow machine.
Use to display a list of objects based on search criteria you specify. You can directly access the properties dialog box of any object in the search output display by clicking that object. See Finding Stateflow Objects for more information.
Chart contained by another chart. See Using Subcharts to Encapsulate Modal Logic.
A state is a substate if it is contained by a superstate.
A state is a superstate if it contains other states, called substates.
Transition between objects residing in different subcharts. See Moving Between Different Levels of Hierarchy with Supertransitions for more information.
A container object for the generated code from the Stateflow charts in a model. The collection of all charts for a model appears as a Stateflow machine. Therefore, target objects belong to the Stateflow machine.
The code generation process can produce these target types: simulation, embeddable, and custom. See Building Targets for more information.
The circumstances under which the system moves from one state to another. Either end of a transition can be attached to a source and a destination object. The source is where the transition begins and the destination is where the transition ends. Usually, the occurrence of an event causes a transition to take place.
Flow path that starts and ends on a state.
A state-to-junction, junction-to-junction, or junction-to-state part of a complete state-to-state transition.
A chart function that specifies logical behavior with conditions, decisions, and actions. Truth tables are easier to program and maintain than graphical functions.
See Truth Table Functions for Decision-Making Logic for instructions on how to use truth tables in Stateflow charts.
 | Directed Event Broadcasting Examples |
Learn how engineers use Stateflow to model state machines in their Simulink models.
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