Network Aspects of Virtualized Industrial Control from the Edge Cloud Enabled by COTS Hardware

Challenges faced by manufacturing industry due to shorter product life cycles, globalization, rising raw material costs and increasing diversity of product variants are addressed by the transformation to Industry 4.0 and Software-Defined Manufacturing. Data availability and flexibly scalable control systems are essential so that software can take over the central and steering role. This required flexibility can be achieved with the help of the principle of virtualization that has become established in information technology, which enables hardware, platforms or entire services to be scaled as required and reduces administrative effort. In automation technology, however, there are additional requirements for real-time, availability and security compared to IT, which require special consideration. In this paper, we elaborate intensively on the current state of the art with respect to technologies relevant for the establishment of an industrial control cloud. We present a concept that enables the virtualization and consolidation of industrial control systems based entirely on open-source software and commercial off-the-shelf server and network hardware. In this context, we investigate different approaches for the network connection of field devices to virtualized controllers. To validate our approach, we perform a sample implementation and present results from both response time measurements and a two-channel measurement to precisely quantify the latency induced by virtualization and networking.