Research And Application Of Safety Control Technology Based On Ether Cat Numerical Control System

Along with the progress of numerical control system networking, industrial Ethernet extending towards field level, additionally the influence of growing information technology, the demand of safety or security is increasing for industrial control domain. The industrial CNC system security technology, not only include traditionally physical safety and functional safety in field level, but start to be concerned with vertical communication processes such as office network. Consequently, in the context of dependable system, namely, able to provide justifiably trusted service, it is necessary to make a further study of dependability by its attribute, methods and threats, moreover, defining the total safety of industrial control system and restrict the range of subsystem or subdomain safety.At the beginning of this article, upon the study and analysis on Ether CAT industrial Ethernet fieldbus through its protocol structure and communication principle, we proposed the objectives of the safety communication based on Ether CAT fieldbus, furthermore analyzed and induced potential safety problems existing in numerical control system communication processes based on stated objectives. Meanwhile, we have studied the structure model of the whole plant level industrial Ethernet, and, according to information dimension, considered the existing problem in hierarchical communication structure. In the second place, after considered safety problems in communication processes vertically or horizontally, and reviewed the current situation of the countermeasures to the safety problems, we combined with the Ether CAT communication structure and communication principles, and put forwards the safety measures towards its communication architecture. Finally, we paid attention to the methods and approaches of information security and system functional safety assessment, then also analyzed and verified experimentally the residual error probability under a defined CRC polynomial.Through the example analysis, we concluded the existing relationship between residual error probability and message length,generating polynomial or bit error probability.