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.