A Full Software NC System For Pneumatic Marking Machine Based On Windows

At present, the trend of numerical control system is open-architecture NC system, and full software NC system is the trend of open-architecture NC system. Pneumatic marking machine is a product of mechanical and electronic integration designed for use in a wide range of automatic industry production applications. The traditional NC framework mode of pneumatic marker based on windows is"PC + special NC controller", which could not make the NC kernel fully open though belonging to the category of open-architecture. The main problem with this traditional mode is that a mass of print data between PC and special NC controller need to encode and pack, so decoding this complex data must reduce system Real-time performance, and increase instabilities and interference of system.To deal with the outstanding problems existing in the traditional pneumatic marking machine NC system mentioned above, this paper designed a full software pneumatic marking machine NC system, which NC framework mode is"PC + stepping motor driver". In this framework mode, PC not only serves for Real-time operations such as interpolation, I/O control, etc. but also serves for Not-Real-time operations such as man-machine conversation, etc.. In this framework mode, stepping motor driver is just an I/O interface board, which serves for isolation, amplification, transform of stepping pulse, and drive stepping motor finally. More important is that data between PC and stepping motor driver is no longer complex data, but digital pulse sequence which can be identified by any stepping motor driver. Because the kernel of system entirely be transplanted into the PC and entirely is open to the user, this software NC system is a real full software NC system.Under current leading windows operating system, such as Windows2000, WindowsXP, it is impossible to access physical port directly, and it is necessary to design bottom driver so that access port indirectly. On the base of functional need and criterion of LPT, this paper redefined 25-pin LPT port used for stepping pulse and other I/O signals. This paper designed bottom LPT driver through configuring the Windows DDK development environment in the Microsoft Visual C++ 6.0, and encapsulated to DLL interface function so that upper applications could call. This work is most important part of print software platform.Finally, according to traits of stepping motor and its driver, and requirements of full-software NC system, this paper presents a method of stepping motor design and designed a stepping motor driver, which is small in size, good in cooling, low in cost and well in performance.