A software oriented CNC system based on Linux/RTLinux

The software-oriented CNC is one of the ideal solutions for open architecture CNC. However, its implementation is a difficult task, especially the guarantee of system's real-time performance. In this paper, a software oriented CNC system named Lin-soft CNC, whose operating system (OS) is Linux with its real-time extension - RTLinux - was proposed and depicted. The proposed system consists of four layers: the GUI, non-real-time layer, real-time layer and driver layer. Both the system and subsystem layout are detailed, along with the relevant implementation detail, such as the hierarchy design and the data communication between layers. Furthermore, the real-time layer has been identified as the kernel of the system, in which a simple and effective strategy - rational design of data buffer and high precision period of the real-time thread - is adopted to guarantee the real-time performance. At last, the prototype controller and test results are present.