Field Level The Reliability Of High-speed Ethernet Technology Research

Ethernet's potential in complete and seamless information integration from field control level to management level in enterprise is now gradually developing deeper towards field control level, and managing to amalgamate with other forms of control network. In this thesis, on the basis of introduction on the characteristics and requirement of industrial automation network, by comparing Ethernet based industrial control with traditional fieldbus, we've discussed advantages and disadvantages related to the applications of Ethernet in control field. Ethernet has obvious advantages such as open, cost-effctive, supported by many popular hardwares and softwares, but it also has intrinsical disadvantages such as uncertainty, non-realtime, low reliability and low security, which are all the facts control network requires baddly.We've also discussed how to improve the performance of Ethernet by using some mathmatic theories such as queueing theory. Importing distributed priority control into collision detection can reduce uncertainty effectively; RETHER, RTCC and ARTC are all the protocols with improvements on real-time, which make ethernet into real-time ethernet; Technology of fault-tolerant and redundancy, enhancement on performance on anti-interfere of transmission lines, firewalls all improve the reliability and security of Ethernet. Based on ARTC, this paper presents the architecture of advanced real-time ethernet with high reliability and high speed on field control level. We've done research on the technology of reliability from several ways, such as system architechture, commmunication protocol, transmission channals, network characteristics, functional modules and hardware settings. This paper presents another kind of ethernet adapter -- X signal--ethernet transmission adapter (xETA). X signal is any kind of signal in the industrial field. xETA can easily be used to connect many low-speed field equipments with ethernet (especially ARTC). It can also reduce the budget for upgrade control network. Based on requirements on environment and reliability of xETA, the adapter is designed as the most compact one by using highly-integrated and low-cost chips. Keil C51 is used in design of the software to improve efficiency of development. xETA also offers highly efficient buffer management and flexible paraments configuration, which balance simple control logic of software and high rate of hardware very well.Especially, this paper presents the design and realization of dual-channal ethernet adapter based on PC/104 bus specification and its corresponding driver. This mechanism can offer basic functions such as backup, auto-switch and auto-isolation of transmission channals and interfaces. It can guarantee the high-reliability of ethernet by using error correcting. The product can set the NIC interrupt and I/O base address manually and set the NIC MAC and operating mode by running the driver, which shows the flexblity of the mechanism.At last, this paper give out some tentative plans and some suggestions about the related technologies and research thought of lucubrating the industrial ethernet technology,Such as net speed,hardware integration ,generalization ,power management and embedded OS. Research on the project also indicates that its opening and standardization is the precondition for tis technology's prevalence.