The Research Of The PLC Function In CNC Machine Tools

With the development of CNC technology, the PLC function of CNC machine tool has become an indispensable feature of CNC machine tools. However, CNC machine tools and PLC function in China development has lagged behind some other countries. The PLC function of CNC machine tools need further improvement. This paper begin with status of PLC function, taken depth research of the PLC functionality of the CNC machine. The PLC to CNC machine tools is divided into three parts.1. The first part is the PC software development and implementation. It mainly research the PLC ladder program software in VC++ environment. The introduction of function block programming, simplifying the difficulty of ladder programming. Using a stack algorithm achieved ladder logic into Instruction List, and ultimately to generate the file which can identified by CNC machine tools. At the same time, analysis each logical of language instruction, and then achieve the Instruction List to the ladder diagram.2. Research PLC function on CNC terminal, in order to facilitate and to distinguish with industrial PLC, PLC on CNC terminal is called PMC. This section is divided the PMC function into ladder editing, displays, I/O status display and decode, and then discussed and implemented. 3. Finally, research and analysis several common communication of CNC machine tools. Using the CAN bus communication, access to I/O points and ladder components real-time status, and display in the system interface, achieve the PMC ladder of condition monitoring and I/O point status display.In summary, this paper mainly research the PLC function of CNC machine tools. And decomposition the PLC function and then discussed separately, at last, through practical application, the theory is proved correct.