Stateflow.Chart

Graphical representation of a finite state machine

Description

Use a Stateflow.Chart object to create a graphical representation of a finite state machine based on a state transition diagram. In a Chart block, states and transitions form the basic building blocks of a sequential logic system. States correspond to operating modes and transitions represent pathways between states. For more information, see Model Finite State Machines by Using Stateflow Charts and Create Charts by Using the Stateflow API.

Creation

To create a Stateflow.Chart object, call the function sfnew. For example, to create an empty chart in a new Simulink^® model called myModel, enter:

sfnew myModel

Alternatively, you can add a new chart to an existing model by using the function add_block (Simulink):

add_block("sflib/Chart","myModel/Chart")

Then, to access the Stateflow.Chart object, call the find function for the Simulink.Root object:

chart = find(sfroot,"-isa","Stateflow.Chart", ...
    Path="myModel/Chart");

Properties

Stateflow^® API objects have properties that correspond to the values you set in the Stateflow Editor. To access or modify a property, use dot notation. To access or modify multiple properties for multiple API objects, use the get and set functions, respectively. For more information, see Modify Properties and Call Functions of Stateflow Objects.

Content

Name — Name of chart

"Chart" (default) | string scalar | character vector

Name of the chart, specified as a string scalar or character vector.

ActionLanguage — Action language

"MATLAB" (default) | "C"

Action language used to program the chart, specified as "MATLAB" or "C". For more information, see Differences Between MATLAB and C as Action Language Syntax.

StateMachineType — State machine semantics

"Classic" (default) | "Mealy" | "Moore"

State machine semantics implemented by the chart, specified as "Classic", "Mealy", or "Moore". For more information, see Overview of Mealy and Moore Machines.

SupportVariableSizing — Whether chart supports variable-size data

true or 1 (default) | false or 0

Whether the chart supports variable-size data, specified as a numeric or logical 1 (true) or 0 (false). For more information, see Declare Variable-Size Data in Stateflow Charts.

TreatDimensionOfLengthOneAsFixedSize — Whether chart treats output data with dimension of length 1 as fixed size

true or 1 (default) | false or 0

Since R2023a

Whether the chart treats output data with a dimension of length 1 as fixed size, specified as a numeric or logical 0 (false) or 1 (true). When this property is true, the chart treats output data that have at least one dimension of length 1 as fixed size, regardless of whether you specify the data as having variable size. When this property is false, the chart treats output data as variable size if you specify the data as having variable size.

State Decomposition

Decomposition — Decomposition of substates

"EXCLUSIVE_OR" (default) | "PARALLEL_AND"

Decomposition of substates at the top level of containment in the chart, specified as "EXCLUSIVE_OR" or "PARALLEL_AND". For more information, see Define Exclusive and Parallel Modes by Using State Decomposition.

Chart Initialization

ExecuteAtInitialization — Whether to initialize state configuration

false or 0 (default) | true or 1

Whether to activate the chart with the start of simulation, specified as a numeric or logical 1 (true) or 0 (false). For more information, see Execution of a Chart at Initialization.

StatesWhenEnabling — Behavior of states when event reenables chart

"" (default) | "held" | "reset"

Behavior of the states when a function-call input event reenables the chart, specified as one of these values:

• "" — The chart does not contain function-call input events.

• "held" — The chart maintains the most recent values of the states.

• "reset" — The chart reverts to the initial conditions of the states.

For more information, see Control States in Charts Enabled by Function-Call Input Events.

InitializeOutput — Whether to initialize output data

false or 0 (default) | true or 1

Whether to initialize the output data every time the chart wakes up, specified as a numeric or logical 1 (true) or 0 (false). For more information, see Initialize outputs every time chart wakes up.

Active State Output

HasOutputData — Whether to create active state data output

false or 0 (default) | true or 1

Whether to create an active state data output port for the chart, specified as a numeric or logical 1 (true) or 0 (false). For more information, see Monitor State Activity Through Active State Data.

OutputData — Active state data object

Stateflow.Data object

This property is read-only.

Active state data object for the chart, specified as a Stateflow.Data object. This property applies only when the HasOutputData property for the chart is true.

OutputPortName — Name of active state data object

string scalar | character vector

Name of the active state data object for the chart, specified as a string scalar or character vector. This property applies only when the HasOutputData property for the chart is true.

OutputMonitoringMode — Monitoring mode for active state output

"ChildActivity" (default) | "LeafStateActivity"

Monitoring mode for the active state output data, specified as "ChildActivity" or "LeafStateActivity".

EnumTypeName — Name of enumerated data type for active state data object

string scalar | character vector

Name of the enumerated data type for the active state data object for the chart, specified as a string scalar or character vector. For more information, see Enum Name.

DoNotAutogenerateEnum — Whether to define enumerated data type manually

false or 0 (default) | true or 1

Whether to define the enumerated data type for the active state data output manually, specified as a numeric or logical 1 (true) or 0 (false). For more information, see Define State Activity Enumeration Type.

Discrete and Continuous-Time Semantics

ChartUpdate — Activation method for chart

"INHERITED" (default) | "CONTINUOUS" | "DISCRETE"

Activation method for the chart, specified as "CONTINUOUS", "DISCRETE", or "INHERITED".

SampleTime — Sample time for activating chart

"-1" (default) | string scalar | character vector

Sample time for activating the chart, specified as a string scalar or character vector. This property applies only when the ChartUpdate property for the chart is "DISCRETE".

EnableZeroCrossings — Whether to enable zero-crossing detection

true or 1 (default) | false or 0

Whether to enable zero-crossing detection on state transitions in the chart, specified as a numeric or logical 1 (true) or 0 (false). This property applies only when the ChartUpdate property for the chart is set to "CONTINUOUS". For more information, see Disable Zero-Crossing Detection.

VariantActivationTime — Which block variants Stateflow analyzes

update diagram analyze all choices (default) | code compile

Which block variants Stateflow analyzes during simulation and code generation, specified as one of these values:

• update diagram analyze all choices — Stateflow analyzes both active and inactive choices for incompatibilities in signal attributes and generates code only for the active choice.

• code compile — Stateflow analyzes both active and inactive choices of variant transitions and generates code for both the active and inactive choices. The choices are enclosed in C preprocessor conditional statements #if and #endif that are conditionally compiled when you compile the generated code.

Super Step Semantics

EnableNonTerminalStates — Whether to enable super step semantics

false or 0 (default) | true or 1

Whether to enable super step semantics for the chart, specified as a numeric or logical 1 (true) or 0 (false). For more information, see Super Step Semantics.

NonTerminalMaxCounts — Maximum number of transitions in one super step

1000 (default) | scalar

Maximum number of transitions the chart can take in one super step, specified as an integer scalar. This property applies only when the EnableNonTerminalStates property for the chart is true.

NonTerminalUnstableBehavior — Behavior if super step exceeds maximum number of transitions

"Proceed" (default) | "Throw Error"

Behavior if a super step for the chart exceeds the maximum number of transitions specified in the NonTerminalMaxCounts property before reaching a stable state, specified as one of these values:

• "Proceed" — The chart goes to sleep with the last active state configuration.

• "Throw Error" — The chart generates an error.

This property applies only when the EnableNonTerminalStates property for the chart is true.

Exported Functions

ExportChartFunctions — Whether to export chart-level functions

false or 0 (default) | true or 1

Whether to export chart-level functions to other blocks in the Simulink model, specified as a numeric or logical 1 (true) or 0 (false). For more information, see Export Stateflow Functions for Reuse.

AllowGlobalAccessToExportedFunctions — Whether exported functions are globally visible

false or 0 (default) | true or 1

Whether exported functions from the chart are globally visible in the Simulink model, specified as a numeric or logical 1 (true) or 0 (false). When this property is enabled, blocks throughout the model can call functions exported from the chart without using qualified notation. This property applies only when the ExportChartFunctions property for the chart is true.

Integer and Fixed-Point Data

SaturateOnIntegerOverflow — Whether data saturates on integer overflow

true or 1 (default) | false or 0

Whether the data in the chart saturates on integer overflow, specified as a numeric or logical 1 (true) or 0 (false). When this property is disabled, the data in the chart wraps on integer overflow. For more information, see Handle Integer and Enumeration Overflow for Chart Data.

TreatAsFi — Inherited Simulink signals to treat as fi objects

"Fixed-point" (default) | "Fixed-point & Integer"

Inherited Simulink signals to treat as Fixed-Point Designer™ fi objects, specified as one of these values:

• "Fixed-point" — The chart treats all fixed-point inputs as fi objects.

• "Fixed-point & Integer" — The chart treats all fixed-point and integer inputs as fi objects.

This property applies only to charts that use MATLAB^® as the action language.

EmlDefaultFimath — Default fimath properties

"Same as MATLAB Default" (default) | "Other:UserSpecified"

Default fimath properties for the chart, specified as one of these values:

• "Same as MATLAB Default" — Use the same fimath properties as the current default fimath object.

• "Other:UserSpecified" — Use the InputFimath property to specify the default fimath object.

This property applies only when the ActionLanguage property of the chart is "MATLAB".

InputFimath — Default fimath object

string scalar | character vector

Default fimath object, specified as a string scalar or character vector. When the EmlDefaultFimath property for the chart is "Other:UserSpecified", you can use this property to:

• Enter an expression that constructs a fimath object.

• Enter the variable name for a fimath object in the MATLAB or model workspace.

This property applies only to charts that use MATLAB as the action language.

Code Generation

GeneratePreprocessorConditionals — Whether generated code includes a preprocessor conditional

false or 0 (default) | true or 1

Whether the generated code includes a preprocessor conditional statement for the variant conditions in the chart, specified as a numeric or logical 1 (true) or 0 (false). This property applies only when generating code with Embedded Coder^®. For more information, see Control Indicator Lamp Dimmer Using Variant Conditions.

C Action Language

EnableBitOps — Whether to use bit operations

false or 0 (default) | true or 1

Whether to use bit operations in state and transition actions in the chart, specified as a numeric or logical 1 (true) or 0 (false). This property applies only to charts that use C as the action language.

Debugging

Debug — Debugger properties

Stateflow.ChartDebug object

Debugger properties for the chart, specified as a Stateflow.ChartDebug object with this property:

• Breakpoints.OnEntry — Whether to set the On Chart Entry breakpoint, specified as a numeric or logical 1 (true) or 0 (false).

For more information, see Set Breakpoints to Debug Charts.

Example: chart.Debug.Breakpoints.OnEntry = true;

Graphical Appearance

Editor — Editor

Stateflow.Editor object

This property is read-only.

Editor for the chart, specified as a Stateflow.Editor object. You can use this object to control the position, size, and magnification level of the Stateflow Editor window.

Visible — Whether editor is displaying chart

true or 1 | false or 0

Whether the Stateflow Editor window is displaying the chart, specified as a numeric or logical 1 (true) or 0 (false).

ChartColor — Background color

[1 0.9608 0.8824] (default) | [red green blue]

Background color for the chart, specified as a three-element numeric vector of the form [red green blue] that specifies the red, green, and blue values. Each element must be in the range between 0 and 1.

StateColor — Color for states

[0 0 0] (default) | [red green blue]

Color for the boxes, functions, and states in the chart, specified as a three-element numeric vector of the form [red green blue] that specifies the red, green, and blue values. Each element must be in the range between 0 and 1.

TransitionColor — Color for transitions

[0.2902 0.3294 0.6039] (default) | [red green blue]

Color for transitions in the chart, specified as a three-element numeric vector of the form [red green blue] that specifies the red, green, and blue values. Each element must be in the range between 0 and 1.

JunctionColor — Color for junctions

[0.6824 0.3294 0] (default) | [red green blue]

Color for junctions in the chart, specified as a three-element numeric vector of the form [red green blue] that specifies the red, green, and blue values. Each element must be in the range between 0 and 1.

StateFont — Font for state labels

Stateflow.StateFont object

Font for the box, function, and state labels in the chart, specified as a Stateflow.StateFont object with these properties:

• Name — Font name, specified as a string scalar or character vector. This property also determines the font for annotations in the chart.

• Angle — Font angle, specified as "NORMAL" or "ITALIC".

• Weight — Font weight, specified as "NORMAL" or "BOLD".

• Size — Default font size for new boxes, functions, and states, specified as a scalar. This property also determines the default font size for new annotations in the chart.

Example: chart.StateFont.Name = "Arial";

Example: chart.StateFont.Angle = "ITALIC";

Example: chart.StateFont.Weight = "BOLD;

Example: chart.StateFont.Size = 8;

StateLabelColor — Color for state labels

[0 0 0] (default) | [red green blue]

Color for the box, function, and state labels in the chart, specified as a three-element numeric vector of the form [red green blue] that specifies the red, green, and blue values. Each element must be in the range between 0 and 1.

TransitionFont — Font for transition labels

Stateflow.TransFont object

Font for the transition labels in the chart, specified as a Stateflow.TransFont object with these properties:

• Name — Font name, specified as a string scalar or character vector.

• Angle — Font angle, specified as "NORMAL" or "ITALIC".

• Weight — Font weight, specified as "NORMAL" or "BOLD".

• Size — Default font size for new transitions, specified as a scalar.

Example: chart.TransitionFont.Name = "Arial";

Example: chart.TransitionFont.Angle = "ITALIC";

Example: chart.TransitionFont.Weight = "BOLD";

Example: chart.TransitionFont.Size = 8;

TransitionLabelColor — Color for transition labels

[0.2902 0.3294 0.6039] (default) | [red green blue]

Color for the transition labels in the chart, specified as a three-element numeric vector of the form [red green blue] that specifies the red, green, and blue values. Each element must be in the range between 0 and 1.

Hierarchy

Machine — Machine that contains chart

Stateflow.Machine object

This property is read-only.

Machine that contains the chart, specified as a Stateflow.Machine object.

Path — Location of chart in model hierarchy

character vector

This property is read-only.

Location of the chart in the model hierarchy, specified as a character vector.

Dirty — Whether chart has changed

true or 1 | false or 0

Whether the chart has changed after being opened or saved, specified as a numeric or logical 1 (true) or 0 (false).

Locked — Whether chart is locked

false or 0 (default) | true or 1

Whether the chart is locked, specified as a numeric or logical 1 (true) or 0 (false). Enable this property to prevent changes in the chart.

Iced — Whether chart is locked

false or 0 (default) | true or 1

This property is read-only.

Whether the chart is locked, specified as a numeric or logical 1 (true) or 0 (false). This property is equivalent to the property Locked, but is used internally to prevent changes in the chart during simulation.

Identification

Description — Description

"" (default) | string scalar | character vector

Description for the chart, specified as a string scalar or character vector.

Document — Document link

"" (default) | string scalar | character vector

Document link for the chart, specified as a string scalar or character vector.

Tag — User-defined tag

[] (default) | any data type

User-defined tag for the chart, specified as data of any type.

Id — Unique identifier

scalar

This property is read-only.

Unique identifier, specified as an integer scalar. Use this property to distinguish the chart from other objects in the model. The value of this property is reassigned every time you start a new MATLAB session and may be recycled after an object is deleted.

Object Functions

find	Identify specified objects in hierarchy
getChildren	Identify children of object
defaultTransitions	Identify default transitions in specified object
dialog	Open properties dialog box
view	Display object in editing environment
fitToView	Zoom in on graphical object

Examples

Create Empty Stateflow Chart

Call the function sfnew to open a new Simulink model that contains an empty Stateflow chart.

sfnew

Access the Simulink.Root object by calling the sfroot function.

rt = sfroot;

Access the Stateflow.Chart object by calling the find function for the Simulink.Root object.

chart = find(rt,"-isa","Stateflow.Chart");

Version History

Introduced before R2006a

R2024a: Implicit ordering of transitions and parallel states will be removed

In a future release, the property UserSpecifiedStateTransitionExecutionOrder will be removed. This property applies only to charts that use C as the action language.

• When you enable this property, charts execute transitions and parallel states in the order you created them. You can also manually determine the execution order.

• When you disable this property, charts execute transitions and parallel states according to an implicit order defined by physical position.

  Transitions execute according to:

  1. The hierarchical level of the parent of each transition.

  2. The labels of the transition, in this order:

     1. Labels with events and conditions.

     2. Labels with events.

     3. Labels with conditions.

     4. No label.

  3. The angular surface position of the transition source. The transition with the smallest clock position has the highest priority. For example, a transition with a 2 o'clock position has a higher priority than a transition with a 4 o'clock position. A transition with a 12 o'clock source position has the lowest priority.

  Parallel states execute in this order:

  1. Top to bottom.

  2. Left to right.

To ensure your implicitly ordered charts remain compatible, set UserSpecifiedStateTransitionExecutionOrder to true.

R2023b: Convert to state transition table

To convert a chart to a state transition table, use the function convertToSTT.

R2023a: Specify how to treat output data with dimension of length 1

With the new property TreatDimensionOfLengthOneAsFixedSize, you can specify how charts treat output data when at least one dimension has length 1. Prior to R2023a, charts treat output data with a dimension of length 1 as fixed size, regardless of whether you specify the data as having variable size.