基于菊花链回路的工业Ethernet I/O系统改造

为解决旧式I／0系统控制层与现场层采用协议不统一导致的开放性差及中、远距离成本高等问题，将Ethernet技术延伸应用到现场级控制通信中，使现场层和控制层基于统一的Ethemet协议。在基于旧式远程I／O子站与以太网远程I／O子站的异同点分析的基础上，开展了基于菊花链回路的工业EthernetI／O系统改造和迁移过程的分析，提出了基于菊花链回路的光纤主回路和长距离热备光纤回路的的构建方法。通过Quantum通信设备，使分布式I／O主站模块、主环路上的DRSs、分布式I／O设备和远程I／O网络构成了菊花链主回路。在子回路中扫描本地分布式I／O设备，DRSs控制来自子回路的分布式I／O设备的数据流，从而保持主回路中远程I／O流量的最高优先级，通过优先级控制不同级别的I／O数据。研究结果表明，该方法既能保证网络的冗余，又能保证网络的高效和时间的确定性。

Improvement of industrial Ethernet I/O system based on daisy chain loop

Aiming at the issues of poor opening performance and high cost in middle and long extent caused by the uniformity of protocol used in control layer and field layer of legacy I/O system, Ethernet technology was used in the communication of filed level control, which makes control layer and field layer use a unified Etheruet protocol. Based on the analysis of the difference of legacy remote I/O sub-station and Eth- ernet 1/O sub-station, the industrial Ethemet I/O system improvement and migration process based on the daisy chain loop was investigated and the constructing method of fiber-optic main circuit and ~ong distance hot standby fiber-optic circuit based daisy chain loop were proposed. The main loop daisy chain was contituted with the distributed I/O master module, the main loop of DRSs, the distributed I/O devices and the remote I/O network by using Quantum communication device. In the sub-loop, local distributed I/O devices were scanned, the distributed I/ 0 data streamed from the sub-loop device was controlled by DRSs to maintain the highest priority remote I/0 traffic in main circuit, to make priority control through the different levels of I/O data. The results indicate that this method not only can ensure network redundancy, but al- so can ensure the network efficiency and time certainty.