工业控制网络对网络的实时性要求很高，不仅要求传输速度快，数据传输还要具有确定性。以太网的通信存在不确定性，不能满足实时性要求，成为以太网应用于工业控制领域的主要障碍。本设计实现的实时以太网［2］就是网络中每个节点的通信被严格地限定在规定时间内，确保在同一网段内同时只有一台在发送数据。关键词：工业以太网；确定性；调度；实时Abstract: Industrial control net is a special applicative network, it demands high desired real time processing and deterministic. Non-deterministic communication of ethernet which can't meet the real time demand of industrial control has become a main obstacle in application on filed device layer network. Real-time Ethernet implemented in this design is to build a high speed , deterministic network over traditional Ethernet . The communication among work stations is limited in deterministic time intervals , which guarantte that only one node can send datas in a certain time.Key words: Industrial Ethernet ; deterministic ; scheduling ; real-time