This part of the IEC 62541 series defines the information model associated with Devices. This document describes three models which build upon each other as follows: " The (base) Device Model is intended to provide a unified view of devices and their hardware and software parts irrespective of the underlying device protocols. " The Device Communication Model adds Network and Connection information elements so that communication topologies can be created. " The Device Integration Host Model finally adds additional elements and rules required for host systems to manage integration for a complete system. It allows reflecting the topology of the automation system with the devices as well as the connecting communication networks. This document also defines AddIns that can be used for the models in this document but also for models in other information models. They are: " Locking model a generic AddIn to control concurrent access, " Software update model an AddIn to manage software in a Device.