All instances of MachineToolType in a Server shall be referenced from the Machines Object as defined in OPC 40001-1. This provides the capability to easily find all machine tools managed in a Server.

The Machines Object may contain other nodes than instances of MachineToolType. As only the MachineToolType offers the MachineIdentificationAddIn as a subtype, no other type defined in this specification can be referenced directly from the Machines Object.