With a new extension of the OPC UA specification, which Beckhoff played a prominent role in helping develop, the publisher/subscriber principle is being introduced into the established and standardised OPC UA communication protocol. Through the early integration of the Pub/Sub UDP extension, Beckhoff has emerged once again as an early adopter of OPC technologies.
One particular advantage is the much simplified configuration resulting from direct integration into the TwinCAT 3 engineering environment. Communication is initiated directly from the TwinCAT 3 runtime, creating a deterministic and therefore real-time-capable communication channel via OPC UA.
Advantages of publisher/subscriber communication
Conventional client/server applications are decoupled from one another in publisher/subscriber-based data communication and no longer need to "know" each other. The publisher simply sends its data, as a UDP multicast in this case, to a multicast group. The subscribers receive the data by subscribing to the multicast group instead of the actual device.
These advantages can be utilised in all areas of machine design, plant engineering and building automation technology. This is especially true in M2M scenarios within machine networks, for example, in small manufacturing systems as well as complex machines and buildings.
According to the current roadmap for the OPC UA specification, this extension is expected to be finalised by the OPC Foundation in early 2017. Accordingly, Beckhoff plans a timely product release in TwinCAT 3.