OnValueChanged(Path, Timestamp, Quality, Value)

The parameters of this events are the following:

•Path: Path to the monitored property

•Timestamp: Timestamp of the property referenced in the Path parameter

•Quality: Quality of the property referenced in the Path parameter

•Value: Value of the property referenced in the Path parameter

This event can be captured by any application instantiating this library. From the moment the RegisterCallback method is used, the COM object starts sending change notifications to the property passed in the Path parameter. For this object to be able to receive these notifications, users must create it with the prototype declared next.

Public Sub OnValueChanged(ByVal link As String, ByVal TimeStamp As Object, ByVal Quality As Short, ByVal Value As Object)

Then users must add a handler to that event in the COM object. In Visual Basic, this is performed according to the next prototype.

AddHandler(e3.OnValueChanged, New E3DataAccessLib._IE3DataAccessManagerEvents_OnValueChangedEventHandler(AddressOf OnValueChanged))

Thus, whenever an event is generated by the E3DataAccess Library, the application receives a call from the OnValueChanged method showing the changed property's Link, the timestamp of the change, the quality, and the new value.