KEBA: OPC UA – AN OVERVIEW OF THE CENTRAL INDUSTRY 4.0 STANDARD

Early on in the course of industrialization, the major market players realized that ultimately, everybody benefits if there is cooperation instead of confrontation in certain areas. In the late 19th century, the first standardization committees were formed in Europe. But conflicting interests have never quite disappeared, even within the various standardization committees. These conflicts mean that frequently, only minimal agreements can be reached.

Devices and technical components made by different manufacturers are only partially compatible. Customers who do not source everything from a single supplier are thus forced to do without parts of the functionality, or must invest the effort of creating it themselves.

Babylonian confusion in industrial communication
The limitation to minimal agreements is not the only obstacle to cooperation. Sometimes, even minimal agreements are missing and instead, competing standards exist. In the industrial sector, this is true in particular for communication. Numerous manufacturers have created their own “standards” for the transmission of data and control commands between sensors, actuators and controllers.

The advancement of the IP networking standard had the potential to overcome this Babylonian confusion of languages. But standard Ethernet is inadequate for the requirements of the industrial sector—and when adapting it to their specific needs, each driver of innovation in industrial networking reverted to backing their own horse.

And yet again, customers were forced to either enter the closed universe of a single manufacturer or pay a hefty price for openness.

From Industry 3.0 to Industry 4.0
The transmission of sensor measurements and simple control commands had thus become possible. However, the next innovation leap exposed new problems. The goal of Industry 4.0 is to network numerous components. This has fractured the vertical orientation of the “automation pyramid”. There are now horizontal connections within the pyramid as well as lateral connections between different machines, systems and even production facilities scattered across the globe.

Within this framework, a meaningful data exchange must be based on consistent data standards. The absence of such conventions was one of the greatest obstacles in the development of Industry 4.0, because combining data from different sources required an enormous programming effort.

Another problem: how to interpret the data? After all, just because items have the same name (e.g., the same variable name) and look the same (in terms of data format, value range, etc.), it does not necessarily follow that they mean the same thing.

The alternative is to adapt the cross-machine data communication in-house, requiring enormous manual effort. Each time a new machine is added or a component is replaced, there is the risk that programs need to be tweaked again. Consequently, only the most important data is covered in such scenarios, in order to keep the effort manageable. But this in turn means losing out on some of the opportunities offered by Industry 4.0.

Centralized standard: OPC UA
The Open Platform Communications Unified Architecture (OPC UA) provides a solution for these problems. OPC UA is a standard for data exchange as a platform-independent, service-oriented architecture (SOA) that permits not only conveying machine data, but also describing this data using machine-readable semantics. This approach makes communication between different network nodes simpler and more efficient.

The OPC Foundation, which maintains and develops the standard, emphasizes the following major benefit realized in OPC UA:

OPC UA: Not one standard among many, but a central component of digitization
The development of OPC US is progressing continuously, with the involvement of manufacturers as well as users, research institutes and various consortiums such as industry associations and standardization committees.

OPC UA is not a standard among many whose future-proof ness is in doubt. It is a central component of the increasing networking and digitization in the industrial sector, and at some point will be a must-have for every machine.