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11.3.45 SendSignalAction




    InvocationAction (from BasicActions ) on page 267


   SendSignalAction is an action that creates a signal instance from its inputs, and transmits it to the target object, where it may cause the firing of a state machine transition or the execution of an activity. The argument values are available to the execution of associated behaviors. The requestor continues execution immediately. Any reply message is ignored and is not transmitted to the requestor. If the input is already a signal instance, use SendObjectAction.


   No additional attributes


   • signal: Signal [1] The type of signal transmitted to the target object.

Issue 8188 - add subsets constraint

   • target: InputPin [1] The target object to which the signal is sent. {Subsets Action::input}


   [1] The number and order of argument pins must be the same as the number and order of attributes in the signal.

   [2] The type, ordering, and multiplicity of an argument pin must be the same as the corresponding attribute of the signal.


Issue 8188 - replace ‘his’ with ‘this’

   [1] When all the prerequisites of the action execution are satisfied, a signal instance of the type specified by signal is generated from the argument values and this signal instance is transmitted to the identified target object. The target object may be local or remote. The signal instance may be copied during transmission, so identity might not be preserved. The manner of transmitting the signal object, the amount of time required to transmit it, the order in which the transmissions reach the various target objects, and the path for reaching the target objects are undefined.

   [2] When a transmission arrives at a target object, it may invoke behavior in the target object. The effect of receiving a signal object is specified in Chapter 13, Common Behaviors. Such effects include executing activities and firing state machine transitions.

   [3] A send signal action receives no reply from the invoked behavior; any attempted reply is simply ignored, and no transmission is performed to the requestor.


   A send signal action is notated with a convex pentagon.

   Signal Type

   Send signal action

   Figure 11.23 - Send signal notation


    See extension in SendSignalAction (as specialized) on page 423.

   Sends a signal to a specified target object.

*Changes from previous UML

   Same as UML 1.5.