Research For The Real-time Data Acquisition System Based EtherCAT Network

Data acquisition systems have been widely used in many application area, and research work is focus on high speed, long distance and distributed system. Industrial Ethernet with flexible, real-time and distribution characteristics, greatly improves the performance of data acquisition system. EtherCAT as an advanced international industrial Ethernet, by modifying the underlying commercial Ethernet MAC protocol, has successfully ultilized of the flexibility of commercial and industrial general-purpose Ethernet fieldbus real-time feature, and is an ideal platform to build a real-time, high-speed distribution data acquisition system.Makes use of experimental ocean wave making as a background, this work developed a new real-time acquisition system control software based on Windows XP+INtime environment EtherCAT. This software uses INtime real-time programming environment to realize real-time communication between EtherCAT master and slave, which ensures high-speed real-time data acquisition of the EtherCAT master. Field tests prove that the software can be successfully applied to experimental ocean wave data collection. The main achievements of this paper are listed as follows:First, to satisfy the need of experimental ocean wave making, several solutions of data acquisition system including hardware and software are analyzed respectively, and the solution that hardware based on EtherCAT network and software based on Windows XP+ INtime real-time data acquisition system is choosed, and the system is specified on functions and sturcture.Second, according to the features of INtime development application and different real-time system functions, the system is divided into host interface program and network communication program, details of two specific program design and implementation are fully described and data communication and synchronization control method between two programs are studied and the specific code in key parts are given. Third, a data processing program studied and developed which is divided into data storage, data playback, and data analysis according to the functions and the specific implementation method is described.Fourth, the real time on-site collection results are obtained through numbers of ocean-made wave experiments, and data-replay and data analysis is carried out. According to the the acquisition process monitoring and store data analysis, real-time and stability of the system are evaluated to verify the feasibility and advantages of the system.