Andreas Hager: I can certainly imagine that, in the future, some processes will be controlled from the cloud. Nevertheless, we'll still need hardware on site to handle data transmission. And as soon as there's time-critical synchronization of sensors and actuators involved, the control intelligence itself will also need to be on site. Even with the unprecedented speeds of technologies like 5G and TSN, it's not enough to completely virtualize all machine controls and move them to the cloud.
Hager: In a modern machine, when motion control sequences have to be precisely synchronized, we're talking about cycle times of well under one millisecond. Anything higher than that slows down the machine and impacts production efficiency. If we look at 5G, the real latency is currently in the double-digit millisecond range. On top of that, you've got the fluctuations that come with wireless connections. That's a dealbreaker for motion control applications – especially wherever safety is involved.
Hager: Not entirely. The basic functions you find in every PLC will still be the same five years from now. Nevertheless, the Internet of Things and cloud computing are introducing entirely new demands. We'll be needing them to not only control the machine, but also collect and evaluate huge volumes of data and make it ready for higher-level systems. We'll also be using 5G for things like secure remote maintenance. So – far from becoming superfluous – the PLC will actually grow in importance by taking on an additional role: as an edge device connected to the cloud.