Research On Real-time Control Technology With EnterCAT Network

With the development and promotion of Ethernet Technology, Industrial Control Ethernet, the Application of Ethernet in Industrial Control Field, is an important trend in current industrial control fieldbus technology. EtherCAT is a high real-time, high reliability, and high-speed industrial Ethernet bus with flexible topology.According to the need of analog signals such as pressure and wave height.etc in the field of sea engineering, a real-time control technology is proposed. A real-time control platform based on EtherCAT Network is developed independently. It realizes the EtherCAT protocol and function of master used Windows XP+RTX(trial version) as software platform. The real-time control technology extends the real-time performance of Windows through RTX, ensures real-time data exchange between control platform and the EtherCAT slave, and achieves real-time industrial control requirements.In this article, firstly, the architecture of RTX and structure of RT-TCP/IP are introduced, the real-time mechanism is analyzed in detail. The real-time performance of both Windows and RTX is compared by experiments.Secondly, this paper gives a brief introduction to EtherCAT network principle. The physical layer, data-link layer and application layer are described specially. Meanwhile, the EtherCAT slave is introduced briefly.Then, according to system design requirements, the function of the EtherCAT master is analyzed. Three methods are proposed to design the master. The method on RTX platform is highlighted.Finally, this article gives details on real-time control applications in data acquisition, the overall structure of the data acquisition system is worked out. In terms of hardware, platform is established by personal computer and the EtherCAT slave; in terms of software, Windows XP+RTX is used as the software platform. By displaying and analyzing data, results show that the real-time control platform not only has reliability and stability but also meets the requirements of real-time control system.