On the use of Ethernet at low level of factory communication systems

The use of Ethernet is currently proposed in industrial plants also at low level of factory communication systems. In this area, where fieldbuses are extensively used, fast data exchange between controllers and sensors/actuators is typically performed. The original version of Ethernet was not able to satisfy to these real-time requirements, but its recent improvements have significantly modified the context. This paper proposes a communication profile based on Ethernet which makes possible its use at low level of factory communication systems, In particular, the implementation of two real-time protocols is analysed. The performances of these protocols are then evaluated and compared with those of two important fieldbuses. (C) 2001 Elsevier Science B.V. All rights reserved.