A Dimension_specification defines a tolerance between two Placed_elements (Origin & Target). Placed_elements can be either a Located_component, a Node or a Fixing_assignment.
The semantics that applies is the following:
- If a Located_component is used, the dimension applies to the reference measurement point of the component (e.g. the front edge of a connector).
- If a component has no unique measurement point (e.g. cable ducts) and is placed on multiple positions in the topology the corresponding Fixing_assignment can be referenced, in order to create an unambigious reference.
- If a Node is used as Placed_element, the dimension applies to the corresponding position of the node (e.g. the bundle position point of a connector, if a connector is placed on the node).