Public Network and Telecontrol Concepts in Virtual Automation Networks

Abstract This paper describes the aspects for the needed integration of public networks (Wide Area Networks) into Virtual Automation Networks as investigated in the respective work package of the equally named EU-funded project VAN. The main aspects when using public network services within automation applications are the following: (1) Real-time capabilities of public networks related to automation tasks; (2) Telecontrol requirements; (3) Provider Contracts (Service Level Agreements); (4) QoS capabilities and network monitoring from automation side. Currently available communication solutions and Service Level Agreements do not support the required capabilities for real-time applications as discrete manufacturing applications. On the one hand nowadays available fieldbus standards are primarily based on cyclic transfer of IO data and do not support distributed applications across subnet boundaries. On the other hand a variety of proprietary and standardised protocols designed to communicate across public networks in telematic systems do exist. Thus fieldbus technologies and telecontrol systems today base on different technologies and protocols. In VAN a common open platform and common means for classical fieldbus tasks and telecontrol tasks are defined to be able to realise Virtual Automation Networks that combine both fielbus and telecontrol related aspects. The activities focus on a seamless integration of real-time and telecontrol functionalities into the common open VAN platform. So the paper focuses on the network related - and not the applicational - aspects and is thus not about networked control.