Open-architecture CNC System Based On RTLinux

At present open-architecture CNC system based on PC has becoming popular, DOS and Windows operating systems have been widely used as its software platform. But neither of them is ideal for the software platform of an open architecture CNC system, because of their limitations for either multi-tasks or real-time control requirements. So, the real-time operating system RTLinux is used to develop the open architecture CNC system.RTLinux is a multi-tasks and real-time operating system with excellent performance, It based on Linux operating system and can run at many hardware platforms. The CNC system based on RTLinux can accomplish real-time multi-tasks scheduling without secondary CPU. The principle and character of RTLinux operating system are studied in this paper with tasks scheduling policy, at the same time the pivotal techniques of real-time application development, kernel real-time thread, interrupt, communication, are studied with the mode of real-time application development.In RTLinux, the application's tasks have to be split into two fields: real time field and non real time field. The architecture of real-time application must be reasonable in order to satisfy its requirement of multi-tasks and real-time. On the premise that analyzing task characteristic of open architecture CNC system the software of CNC system is studied with how to plot out modules and accomplish those modules. The partition and communication of modules are studied in software architecture; the scheduling between tasks is studied in tasks scheduling and how to do; the equidistant outline-mode arithmetic of tool- compensate in tool- compensate module are putted forward in realization of modules, at the same time the tasks of file management, interpretation code, advance disposal, interpolation and plus-minus speed control are studied.The GUI mode in RTLinux is studied: one is GUI based on window system, another is GUI based on character. The effect window system GUI on real-time capability of real-time application is discussed detailed.COMEDI criterion is discussed on the base of summarizing the hardware device driver in RTLinux, at the same time pivotal technique of COMEDI driver is studied and examples are analyzed.Open-architecture CNC System Based on RTLinux can satisfy the request that real time control system for speedy response, accurate time and divinable control.