Research On DNC System With Remote Call And Drip Feed

With the progress of Numerical Control (NC) technology, more and more NC equipments are used in manufacturing enterprise. Then the technology of Distributed Numerical Control (DNC) comes into application increasingly.In application of this technology, there exist some problems, such as the communication distance between NC machines and DNC host is restricted, synchronously control is not supported and the operations are not convenient.In this thesis, on the basis of researches on serial communication, remote call, drip feed and synchronous control, a DNC system based on RS-232 serial device server with the functions of remote call and drip feed is put forwards to solve the problems, and the framework of the DNC system is given. In it, the NC machines are connected to the serial device servers, and the serial device servers are connected to the LAN which is using TCP/IP protocol. The NC machines send a NC program with predefined instructions to the DNC host, then the host analyses the NC program and executes the instructions, so the function of remote call is realized. synchronous control of the communication is realized by the multithread technology.In the thesis, the functions, databases and programs of the DNC system is designed, and it is developed with Visual C++ program and SQL Server 2000 Data Base Management System. It has functions such as remote call, NC program management and so on, and drip feed is supported. The developed system has been applied in Engineering Training Center of NUAA.