Research And Application Of Hybrid Technology Of CNC Fieldbus

Because of the difference of fieldbus protocol,CNC system can not support the hybrid of different fieldbus devices directly.Aiming at the hybrid occasion of NCUC-Bus,EtherCAT,MECHATROLINK-? bus equipment in CNC system,this paper presents a software fieldbus hybrid scheme based on application layer integration,to implement the integration of the three fieldbus on the application layer,and to meet the requirements of the CNC system for its mixed links.Through the analysis of the mixed links of the fieldbus,a software fieldbus hybrid scheme based on application layer integration of the fieldbus three-layer communication model is proposed.The integrated software architecture of the NCUC-Bus,EtherCAT,MECHATROLINK-? fieldbus is realized,which include of the data interface exchange module,the state machine,fieldbus mapping module,configuration file,fieldbus protocol module,fieldbus driver module.Encapsulate the application layer protocol of the different buses,to unify the interfaces of the application layer.Aiming at the one-to-many mapping relation between CNC system and multi-fieldbus devices,each slave device is abstracted from the slave data object,and the bus master is abstracted as the master data object.At the same,the mapping between the upper layer application and each logical master station is used to realize the dynamic correlation between the slave data objects and the master data objects.Through the object dictionary,realize the mapping from the slaves' data of the master data objects and NCUC-Bus,EtherCAT,MECHATROLINK-? fieldbus protocol.Due to the difference of the bus communication mode,such as NCUC-Bus and EtherCAT adopt summation frame,and MECHATROLINK-? uses a single address frame,a scheme of sequential control and parallel communication is proposed.Unified communication cycle,so that the communication card to work in parallel,while in a cycle,each of the fieldbus data is processed in order.The planning scheme of the communication cycle is presented,which can restrain the minimum cycle in parallel operation.At the same time,the communication mode of each fieldbus is abstracted into several stages,such as initialization,device configuration and normal communication.Based on the above research,the integrated driver module,which can support NCUC-Bus,EtherCAT and MECHATROLINK-?,is implemented and applied to the CNC system of HNC-8.The tests about functionality and real-time are done on the prototype of MECHATROLINK-? and the prototype of NCUC-Bus and EtherCAT dual fieldbus to verify the feasibility of the method.And it is applied to HSC430L-A CNC machine of the RS Technology company.