Cyber Physical Systems (CPS) are important building blocks of Industry 4.0, and data is the glue that holds them together. CPS only become a ‘smart factory’ when they are networked. To achieve this, they must be able to obtain all the necessary raw data or information themselves. This works through standardisation. OPC Unified Architecture is one such standard that enables secure, reliable exchange - between sensors, embedded devices, PLCs, PCs, mainframes and even the cloud. The exchanged data is not only transported but is also machine-readable thanks to a semantic description.
‘Global language of production’
The German Machinery and Equipment Manufacturers Association VDMA sees OPC UA as the ‘common language for all machines’, a ‘global language of production’. The standard ensures interoperability, regardless of manufacturer, operating system or programming language. Communication via the Internet no longer utilises Microsoft's DCOM technology (like its predecessor OPC). Its developers have redesigned OPC UA and based it on a service-oriented architecture (SOA). The specifications for this were developed in collaboration between users, manufacturers and various consortia. OPC UA is now an IEC standard that is being further developed in a coordinated manner by the OPC Foundation.
The advantages can already be illustrated using sensor data. Sensors that have to provide important monitoring data in critical systems have often used proprietary data exchange protocols until now. Integration into existing systems was often time-consuming, especially if buffering or analysing the data was also required. An OPC UA-capable sensor, on the other hand, can be integrated without any effort. Systems for plant control, trend monitoring or reporting, which also ‘speak’ OPC UA, can access the sensor data directly. The integrated safety is an additional argument that is particularly useful in industries such as chemicals or pharmaceuticals.
