Study And Application Of CNC Point To-point Communication

Point to-point communication is an important way in CNC communication, applied widely in communication between a CNC system and a PC, and between two CNC systems. The rapid development of modern numerical control technology brings more demands to Point to-point communication.Application of CNC Point to-point communication is studied in this thesis, and communication softwares between a CNC system and a PC through net interface, serial interface and USB interface are developed.Network Point to-point communication software based on NETBIOS interface standard in CNC is difficult to comunnicate with PC based on Windows NT or above version. NETBIOS interface standard is replaced by TCP/IP protocol as TCP/IP protocol is the most universal protocol in network. CNC Point to-point communication is carried out when CNC system communication is based on WATTCP. Communication software is developed between a CNC system and a PC. Owing to EMS memory is limited in CNC system which is based on MS-DOS, disbranching code of WATTCP library is applied to optimize EMS memory allocation.Former serial communication software is on the mode that file transmitting when NC machine is working, CNC system developed by other commpany is difficult to work on it. Improvement of file transmission flow is studied on serial communication standard, by developing a command transmission and feedback system that will resend the datum while receiving error command to manage the process of file transmission. It enhances the speed, universal and stability of serial communication.USB interface is in common use in datum transmission in CNC, and it also supports Point to-point communication. High-speed datum transmission between CNC system and PC by using USB net bridge cable and under USB On-The-Go protocol is studied to expand the USB communication function in CNC.Communication through USB and net interface is faster, while it is more convenient through serial interface. These interfaces are also ready in CNC system, to meet different demand of datum transmission.