Industrial automation must be able to satisfy very strict demands, since a misdemeanor of such a system can lead to a malfunction of the complete system and by this to high economical loss in form of production downtimes or even mechanical destructions and collisions up to personal injuries. One of the most important requirements for automation system is real time capability beside aspects such as security and safety. Fundamentally, real time capability of a system means that a system is able to react under all operating conditions to all events correctly and within the expected time constraints.
Base on the partially detailed considerations of the topic real time this document consists a comprehensive evaluation and investigation of the state of the art in real time for communication systems embedded in automation systems. The real capability of a system is also strictly depending on the internal structure and communication behavior end points such as remote I/O modules, control devices or network components such as hubs , switches, and in particular on the communication stacks and their implementations.
Wireless real time considerations differ from wired real time consideration especially in reliability aspects of the media availability e.g. disturbances impact from reflections by moving parts as vehicles. Wireless real time considerations are WP 3 D03. 1-1 part and thus will not be considered in this deliverable.
Close loop real time control as the most sophisticated control in automation is considered. First basic of close loop controls are given followed by an investigation of the automation modules within a closed loop. As application field manufacturing, process industry, motion control, and building automation are described.
To provide an overview about the capabilities and features of Ethernet based protocols, a classification grid for evaluating the capabilities and features of the different systems and applied for 12 of the most important systems.