The Research And Realization Of Communication Between Principal And Subordinate CNC Systems Based On CAN BUs

Along with rapid development of modern manufacture, the common numerical control systems (Computerized Numerical Control, CNC)don't take on high automatization at machine and they are lack of networking. Because of these limitations, the function expansion of numerical control systems becomes an important heading of numerical control technique development. The research purpose of the thesis is to establish a sort of CNC system architecture with high reliability, networking and high complex. This will make CNC systems to better adapt to the networking and integration development of modern manufacture.At present, the CNC systems with linkage multi-axes are developed both here and abroad and a great many achievements are obtained. In our country, CNC systems with linkage multi-axes are used by relatively few people. Conventional type and economical type numerically-controlled machines account for 70.1% in numerical control equipments, so it has greatly actual meaning to broaden functions of CNC systems applied in CNC machine tools. At the same time, as a result of the rapid development of microelectronic technique, communication technology, computer technology. CAN(Controller Area Network, CAN)which supports serial communication local area network of distributed control and real-time control has been extensively used in datum communication of control systems. Therefore, combined with CAN Bus, principal and subordinate mode CNC systems are designed and in this thesis the KND-K1000MII type CNC system acts as principal CNC system and the KND-KOS type system acts as subordinate CNC system. The principal CNC system communicates with the subordinate CNC system through CAN bus interface. The dominant researches of the thesis are as follows:First of all, on the foundation of analyses about hardware and software structure of principal and subordinate CNC systems, the whole design proposal of principal and subordinate CNC system is put forward according to all function demands.Secondly, STC89C516RD+single chip is chosen as master chip of subordinate CNC system. After the careful analyses about D/A output module, serial port communication module, memory expansion module and I/O output module in inhere hardware circuit, CAN communication interface circuit is designed and all circuit modules are combined together. When the circuit board is accomplished by PADS2005 software, each modular function is debugged. The anti-interference technique problems of system hardware are illustrated.Once again, on the basis of the analyses about software of subordinate CNC system, the flow design of message from operating panel, program design of interpolation algorithm and program design of CAN bus communication are realized according to modularity function. Initializing designing program of CAN bus controller SJA1000, sending and receiving programs and interrupt handling routines are detailedly carried out by C language in CAN bus communication design. iCAN protocol which is application layer protocol established by Guangzhou Zhiyuan Electronics CO., LTD. is introduced at the same time.In the end, the assumption about applying principal and subordinate CNC systems in machine center with chain magazine is brought forward. The respective functions of principal and subordinate CNC systems in machine center are assigned. The superiority of subordinate CNC system as chain magazine is explained. The control process of principal and subordinate CNC systems is illustrated and the frame structure of iCAN protocol is applied in this machine center.