Ethernet TCP/IP in automation: a short introduction to real-time requirements

For more than a decade the experts have tried to convince the users, that Ethernet is not suitable for applications in real-time communication. Only fieldbus are well adapted to the real-time problems in the automation applications. Today several manufactures propose networking solutions based on the Ethernet-TCP/IP networks. The paper presents examples of problems to be solved, when a user intends to replace fieldbus networks by Ethernet-TCP/IP based networks for automation applications.