Virtual Automation Networks

Industrial automation has been dominated by fieldbuses for several decades. Legacy fieldbuses, such as Profibus, were able to provide the required functions, as they were precisely tailored to automation needs. Fieldbuses represent a complex communication solution for automation, and they define automation-specific physical and link layers and a dedicated communication object model. Nevertheless, Ethernet-based communication ubiquitously appearing in offices fostered temptations to bring Ethernet to production. Ethernet provides market-proven cost-effective hardware components with high data rates and immense integration and network management support using the overlaid management protocols. However, Ethernet has not been designed for industrial applications and would fail to fulfill requirements of industrial automation in its generic form. Hence, adaptations in both end devices and sometimes even switching devices had to be carried out. Finally, various industrial requirements were met, and Ethernet-based fieldbuses became state-of-the-art technologies competing with legacy fieldbuses.