Proliferation of standards
What stands in the way of this goal is the current proliferation of communication standards. Although the Ethernet standard (IEEE 802.3), which has been networking PCs for decades and is extremely fast and reliable, has been booming since the early 2000s. But in factories, there can be no question of a standard, because over the course of time, many providers have "bent" Ethernet to such an extent that there are now a dozen different variants that are not automatically compatible with each other. In addition, there are many other fieldbus standards such as Profibus, Modbus, CC-Link and others, which together still account for almost half of all installations.

Real-time capability with TSN
One solution is the Time Sensitive Network, or TSN for short. This is a future standard based on a proposal from the Ethernet committee. Its great advantage is that it does not originate from the automation environment, but from the audio/video sector, and is therefore likely to meet with less rejection and competition from automation specialists. Concert halls have real-time Ethernet so that sound signals from different microphones are always played to the numerous loudspeakers without any delay differences. Even delays of a few milliseconds between audio channels would be noticeable as echoes.

Applied to automation, TSN as a solution based on convergent networks would bring many advantages. All participants in a TSN network are time-synchronized, i.e. they perform the right action at exactly the right time. TSN has different so-called traffic classes with different time windows that allow data to be prioritized according to bandwidth and time fidelity. Information that is important and cannot be delayed can be given a higher priority, and bandwidth and time windows are reserved for this. TSN will be a standardized extension of Ethernet and fully compatible with it. TSN is not yet available to buy in many products, but the first devices and demonstrators already exist.

OPC-UA gives data meaning
TSN ensures that data arrives where it is needed in good time. However, it does not contain any information about what this data means. This is ensured by a second standard: OPC-UA. This is a communication protocol for exchanging data between cyber-physical systems. OPC-UA is now accepted as a quasi-standard in communication for Industry 4.0. However, it is not real-time capable. However, the experts at the Stuttgart-based ISW are already working on this together with standardization committees. "Communication is no longer a unique selling point," says Oliver Riedel. "Anyone who tries to fight TSN or OPC-UA and continues to rely on proprietary solutions will probably not last long."

The topic of security, i.e. defense against hacker attacks, is also still under discussion. There are already good solutions for the safety aspect, i.e. the protection of employees. For example, workers must be able to rely on their machine stopping immediately when they press the red emergency button. Such commands have the highest priority at TSN. With the features described, TSN therefore has the potential to resolve the Babylonian confusion in industrial data communication.