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addDurationConstraint

Add duration constraint to interaction

Since R2025a

    Description

    durationConstraint = addDurationConstraint(start, end, expression) adds a duration constraint between the start occurrence specified by start and the end occurrence specified by end with the expression specified by expression.

    example

    Examples

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    Create a sequence diagram programmatically to describe the scenario of a pedestrian crossing the street at an intersection with traffic lights.

    To learn more about sequence diagrams, see Author Sequence Diagrams Interactively.

    Open Traffic Light Example

    Load the TLExample architecture model.

    model = systemcomposer.openModel('TLExample');

    TLExample architecture model with various components.

    Create a new sequence diagram named 'InhibitCopy'.

    diagram = model.addInteraction('InhibitCopy');

    Add Lifelines

    Add a lifeline for each component in the architecture.

    sourceLifeline = diagram.addLifeline('TLExample/source');
    pollerLifeline = diagram.addLifeline('TLExample/poller');
    switchLifeline = diagram.addLifeline('TLExample/switch');
    lampLifeline = diagram.addLifeline('TLExample/lampController');
    controllerLifeline = diagram.addLifeline('TLExample/controller');

    Get the root fragment and root operand of the interaction.

    rootFragment = diagram.RootFragment;
    rootOperand = rootFragment.Operands(1);

    Add Messages and Fragments

    Add two messages to the root operand.

    sourceToPollerMsg = rootOperand.addMessage(sourceLifeline, "switchout", pollerLifeline, "sw", "rising(sw-1){sw==1}");
    pollerToSwitchMsg = rootOperand.addMessage(pollerLifeline, "switchEvent", switchLifeline, "switchEvent", "switchEvent{switchEvent==1}");

    Add an alternative fragment to the root operand.

    altFrag = rootOperand.addFragment('Alt');

    Specify the guard expressions for each operand of the alternative fragment.

    op1 = altFrag.Operands(1);
    op1.Guard = "switch/inhibit==0";
    op2 = altFrag.addOperand("switch/inhibit==1");

    Add two messages to the first operand of the alternative fragment.

    switchToLampControllerMsg1 = op1.addMessage(switchLifeline, "lampColor", lampLifeline, "switchPed", "switchPed{switchPed==1}");
    switchToControllerMsg = op1.addMessage(switchLifeline, "switchPush", controllerLifeline, "pedRequest", "pedRequest");

    Add a message to the second operand of the alternative fragment.

    switchToLampControllerMsg2 = op2.addMessage(switchLifeline, "lampColor", lampLifeline, "switchPed", "switchPed{switchPed==2}");

    Add Duration Constraints

    Add a duration constraint between the two messages in the first operand of the alternative fragment.

    startEvent = switchToLampControllerMsg1.End;
    endEvent = switchToControllerMsg.End;
    expression = "t > 12msec";
    durationConstraint = diagram.addDurationConstraint(startEvent, endEvent, expression);

    Open Sequence Diagram

    Open the newly created sequence diagram.

    open(diagram);

    Newly created sequence diagram called 'InhibitCopy'.

    Input Arguments

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    Message event corresponding to the start of a duration constraint, specified as a systemcomposer.interaction.MessageEvent object.

    Message event corresponding to the end of a duration constraint, specified as a systemcomposer.interaction.MessageEvent object.

    Expression defining duration constraint, specified as a string.

    An expression of a duration constraint contains:

    • A keyword to represent the duration observation. Use: t or duration.

    • A relational operator. Use: >, <, >=, or <=.

    • A time value.

    • A unit of time. Use: sec, msec, or usec.

    Example: duration < 10sec

    Example: 1 >= t > 3msec

    Output Arguments

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    Added duration constraint, returned as a systemcomposer.interaction.DurationConstraint object.

    Version History

    Introduced in R2025a