Design And Implementation Of The Fieldbus General Application Layer In Full-digital CNC System

With the development of CNC system tends to high performance, high speed, highprecision and open CNC system, development of a full-digital CNC system which isbased on the NC fieldbus technology and meets the open requirements is thedevelopment trend of international high-grade CNC system. However, there are avariety of NC fieldbuses and standards, their protocols and data exchange interfaces aredifferent, their products aren’t compatible with each other, these caused CNC systemonly supports one bus, motion controller module and NC bus module is a highlycoupled relationship, it can’t meet the open requirements of the full-digital CNC system.In order to implement the full-digital CNC system can be compatible with multiplefieldbuses, and achieve the purpose of the NC fieldbus module can be configured. Thispaper researches and develops the NC fieldbus application layer, focuses on resolvingthe following problems.1. Design of a concrete NC fieldbus structure model based on the protocol stack,and a general NC fieldbus application layer architecture. It divids application layer intoapplication interface sublayer and protocol interface sublayer, the former provides aunified service interface to the upper CNC applications, the latter shields the differenceof the lower different fieldbuses.2. Design and implementation of the NC fieldbus general application layer. Thispaper analyzed the required key technologies and gave the correspongding solutions,such as unified station address, application layer protocol datagram format, unit ofsystem, fieldbus configuration structure. The application interface sublayer providedunified service interfaces, such as transmission services, device services, busmanagement services. The protocol interface sublayer realized the service mappingmanagement, protocol mapping management, fieldbus communication card driver.3. Implementation of the filedbus MECHATROLINK III based on the generalapplication architecture, and JL100driver. This paper compiles these into a Linuxkernel module, then applicates it in the Lantian CNC system, configures and tests it.The experimental test verified the feasibility and correctness of the solution,improved the openness and scalability of the CNC system.