Instantiating the Parent Object in the Macro Editor
The DiagramManager is the parent-level object required to access all other ER/Studio Data Architect objects. The DiagramManager object is instantiated when you start the Macro Editor, which means you can immediately start using this object; you do not need to create it. Begin your code with:
Dim ActiveDiagram as Diagram
Set ActiveDiagram = DiagramManager.ActiveDiagram
If you are writing an external application, the parent object must be instantiated as ERStudio.Application. See Instantiating the Parent Object in an External Application.