IEC/TR 62453-41:2009(E), is a technical report. It defines how the common FDT principles are implemented based on the MS COM technology, including the object behavior and object interaction via COM interfaces and specifies the technology specific implementation of the protocol specific functionality and communication services. Althoug it is informative, when this part is applied its requirements shall be implemented as specified. It specifies FDT version 1.2.1.