open platform communications unified architecture (SOA) (OPC-UA)

The Open Platform Communications Unified Architecture(OPC- UA) is a service-oriented architecture for machine-to-machine( M2M) communication. Together with the Data Distribution Service( DDS), it forms the connection technology for Industrie 4.0 industrial applications.

The OPC UA standard has a security architecture with digital certificates according to X.509. The OPC UA server can obtain digital certificates and revocation lists via the Global Directory Service( GDS). The OPC UA architecture consists of several layers. While protocols reside in the lower two layers, the upper two layers are about services. With OPC-UA, the lower layer supports the transport, describes the data model and the modeling rules. The integrated data structures are realized by the layer above. The basic services are handled in the service layers. These include the Data Access( DA), the Alarms and Conditions( AC), the Historical Data Access( HDA) and the programs, which all form the OPC information model.

The Unified Architecture of Open Platform Communications is a meshed network of nodes representing the user data and the metadata. Such a node can be understood as an object with attributes. These attributes can include specific operations such as data access, data access (DA), the alarms and their conditions, or the history of data access.

As application protocol OPC-UA relies on the SOAP protocol.