OPC UA

What is OPC UA?

OPC UA (Open Platform Communication Unified Architecture) is a collection of open and manufacturer-independent industrial communication standards. These define communication on both a horizontal and vertical level. This means that data and information can be exchanged from machine to machine (M2M) as well as from the machine level to higher-level systems and even to the cloud.

What can OPC UA do?

OPC UA enables standardised data and information exchange between different devices, machines and services via an internet protocol-based network. This makes communication completely platform-independent. The programming language in which the specific software was written or the operating system on which the application runs have no influence and therefore do not form any limits.

Within a service-oriented architecture, an object-oriented model of the machine with its properties and interfaces is defined. The model contains both the properties themselves and their semantics. This means that each participant within an OPC UA network describes itself and can be integrated into a communication.

In addition to the classic architecture for communication based on the client-server principle via TCP or http, OPC UA also offers the possibility to support publish-subscriber mechanisms via AMQP or MQTT. This has the advantage that each client no longer has to make a request to the server, which is then processed individually, but that messages can be sent quickly and simultaneously to one or many recipients without specific request and feedback.

What about data security around OPC UA?

Data security is a fundamental and increasingly important aspect in today's world. During the development of the OPC UA standards, this point was therefore considered intensively from the beginning and embedded in the protocol. Thus there are three security levels, which refer to the transport level, application level and user level and can be scaled according to the application purpose and risk classification. Access rights are defined, so that the machine builder remains master of his data and can distribute it in a targeted and controlled manner.

OPC UA contains both general specifications that must be fulfilled in general, as well as industry-specific data models that are summarised in Companion Specifications. These standardised information models represent similar machines from different manufacturers. The Companion Specifications define which machine type-specific data can be exchanged. This facilitates the implementation and the associated networking of the most diverse machines in a production facility.

With all these advantages and properties, OPC UA forms a basic building block for the connection of Industry 4.0, (Industrial) Internet of Things and Machine 2 Machine communication and the associated digitisation of production.