Ethernet is now conquering the field level in automation technology. Realtime behavior is a knock-out criterion therefore. This paper deals with the key concepts for guaranteed realtime behavior using Ethernet, based on the requirements of factory automation. A classification of the vendor-driven approaches that are currently under discussion for realtime Ethernet is provided.

We address the issue of efficiently automating assume-guarantee reasoning for simulation conformance between finite state systems and specifications. We focus on a non-circular assume-guarantee proof rule, and show that there is a weakest assumption that can be represented canonically by a deterministic tree automata (DTA). We then present an algorithm L that learns this DTA automatically in an...