You can use the following API to retrieve the last signal instance from a runtime object. It is equivalent to $signal$.
 

public static SignalInstance getLastSignal(Object_ o) {
...
}


The following code fragment shows how to get the last signal instance in the event pool of a specified object using ALH API

ALH.getLastSignal(o);

 

It returns the Instance of the following

fUML.Semantics.CommonBehaviors.Communications.SignalInstance.