The nightmare scenario is omnipresent: PLCs are stuck in containers along the supply chain and the cost of available devices is exploding. At the same time, digitalization promises new opportunities. Machine and plant manufacturers and their customers, the operators of these systems, are operating in this environment. A market environment "that is now really playing into the hands of the next generation of industrial controllers," says Domenik Vögel, Product Marketing at Codesys.

According to Vögel, the increasing abstraction of control technology has proven its worth: "Starting with mechanical control systems at the beginning of industrialization and moving on to electrical, electronic and purely software-based control systems, the 'tangible' substructure has become increasingly detached from the software." In the case of virtual controllers, this goes so far that they still run on physical computer platforms, "but now the entire PLC is virtualized using containers, e.g. Docker, and hypervisors." Just as with virtual drives or computers, a description file defines the functional properties and interfaces of the virtualized device - including programmability according to IEC 61131-3 and parameterizable additional features such as visualization, motion control, CNC or robotics. With the "Coded Processing" and "Diversified Encoding" technologies, this is even possible for functional safety requirements up to Safety Integrity Level 3 (SIL 3) in accordance with IEC 61508. V-LAN ports are defined in suitable switches for accessing I/Os via Ethernet-based protocols. This allows data to be exchanged with the field level in real time as usual via Industrial Ethernet protocols such as Ethercat or Profinet. "Users can now create virtual controllers with any functionality and performance based on the description files - even in any number depending on the performance of the underlying platform," says Vögel.

And how do these options actually help to overcome the challenges mentioned? Vögel: "It no longer matters what exact properties the underlying hardware platform has for the virtual controllers, as long as containers or hypervisors are available. This allows manufacturers and operators to switch to any device if required - from open industrial platforms such as IPCs to IT servers." Due to the networking of the systems, the control hardware no longer needs to be located in the control cabinet. It can be commissioned and maintained centrally by IT personnel, and even by the operator himself if necessary. One powerful piece of hardware can therefore replace several dedicated PLCs. "This results in significant cost savings in terms of procurement, installation, operation and updates, as well as new freedom in terms of device selection," says Vögel, listing the advantages. In addition, by distributing parts of the application to virtual controllers, microservices can be implemented, just like in IT. And last but not least: "IT security can also be massively hardened through sensible demarcation of the application."

Codesys at the SPS 2022: Hall 7, Stand 580