OPC UA Information Modeling Method and Xml Definition

Abstract

Through the different nodes in the address space of OPC UA Server, different OPC UA Clients can get a data set full of information, which includes variables, objects, methods, events and types. Customized data types can also be defined in the set. OPC UA Clients need to access the relevant type definition first, which describes the information structure and the encoding rules of the nodes they want to access. So, it's important to define a vendor specific type for a resource-constrained device server, and try to simplify the Complex data model. This article describes the basic structure of the standard OPC UA Address Space, which nodes are mandatory and which are optional in the UA Server. It proposes the principal of building a vendor UA Server, and introduce the open source tool UA-Model Compiler, which can help vendor to customize the minimal namespace0 contained in the UA Server.