Research On Real-time Operating System Based On Configuration And Plc

PLC (Programmable Logic Controller) and DCS (Distributed Control System) are the two major pillars of industrial control. With the constant development of computer technology and the continuous improvement of industrial control requires, pure PLC control and DCS control are gradually unable to meet the requirements of industrial modernization, and so a new type of PLC control system or new DCS control system is emerged. The new PLC control system has simple DCS control functions, while the new DCS control system also has simple PLC control functions, both show a cross-cutting trend. Therefore, the study of a high performance and high-quality embedded computer products by collaborating on controlling industrial field with PLC and DCS is of great significance and value for technology development of PLC and DCS.This paper analyzes and researches configuration (configuration is part of DCS) and PLC control system, and develops an embedded real-time specific operating system (CASS-RTOS) based on characteristics of the configuration tasks and the PLC control tasks. CASS-RTOS can schedule and manage configuration tasks and PLC control tasks and coordinate them to control industrial field. The research result is applied to actual projects.The primary work and research of this paper can be summarized as follows:(1)Analyze and study the characteristics and development of DCS and PLC control system, propose an idea of a new PLC control system with configuration control algorithm based on operating system.(2)Analyze and study status and development of embedded operating systems, discuss advantages and disadvantages of several popular embedded operating systems, and pose an embedded real-time proprietary operating system for supporting configuration and PLC control.(3)According to the object characteristics of configuration and PLC control system, analyze CASS-RTOS kernel structure and put forward CASS-RTOS architecture and design goals.(4)Pose CASS-RTOS memory management program with analyzing and studying memory management strategy and model.(5)Analyze concept and characteristics of processes, threads and tasks, discuss process of interrupt handling and interrupt handling method, study common approaches of tasks synchronization and mutual exclusion, and pose processing solutions of CASS-RTOS tasks synchronization.(6)Focus on analysis and discussion of CASS-RTOS tasks scheduling strategy. At first, study several tasks scheduling strategies, and then put out CASS-RTOS tasks scheduling algorithm design on the basis of the application object characteristics. Establish task model, classify and cut out system tasks based on double-cut technology, and manage them by opening corresponding priority dispatching threads, the research gives an approach for using small threads to realize micro-kernel tasks scheduling.(7)Realize the embedded real-time proprietary operating systems based on configuration and PLC control with the design ideas of CASS-RTOS, and discuss its applications and transplantation.In order to test CASS-RTOS functionality and performance, the author designs and realizes a generation platform of PLC control systems embedded configuration algorithm on the Cortex M3 processor, and designs an experiment. The experiment controls the four synchronous motor control with PLC fast logic task, PLC slow logic task and configuration control task, to inspect CASS-RTOS functions of achievement. Experimental results show that CASS-RTOS kernel is small and has strong portability, high stability as well as high reliability.At present, many embedded operating systems are already very perfect. Compared with them, CASS-RTOS has only achieved the basic functions of operating system, improving the functional aspects needs further analysis, research and debugging. When combined with the requirements of industrial control, to develop a more mature product, needs more in-depth study. The paper has done in-depth research for small-scale embedded real-time specific operating system in specific areas and high-performance PLC control system study is useful to explore and try.