The Embedded Softplc Running System Design Based Onarm

The traditional PLC was widlely used in the industrial control filed and other filed,with the advantage of high reliability,strong anti-jamming capacity,specialization,modular and so on. But the proprietary of software and hardware structure of traditional PLC became the key cause of restrictions on PLC further development. The SoftPLC based on PC platform has been developed quickly, with the advantage of developped structure, because of the real-time defecttion and the shortage of cost control for SoftPLC based on PC platform, the embedded softPLC was produced, with the fast development of embedded system. The embedded softPLC not only achieved the functions of SoftPLC based on PC platform, but also possessed the features of embedded system such as: real-time,the flexibility of resource configuration,the const control and so on.The embedded SoftPLC was consisted of development system and running system. The development system runns on PC platform, the running system runns on embedded system. The running system was the core partition of embedded SoftPLC. This paper mainly researched the realization of running system. Cosidering the features of powerful function,the open source code,the multi-hardware supportting and the easy porting of Linux operating system, we choosed the embedded linux operating system as the software platform for the embedded SoftPLC. Since the linux operating system is a standard time-sharing operating system, we proposed a solution to achieve the real-timre transformation of linux operating system by the way of using the RTAI real-time core. In this paper we analize the implementation principle and the main compositon of RTAI, at last we port the RTAI real-time core to s3c2410 ARM platform by the way of analizing the core source code and finally constructted the real-time environment for embedded SoftPLC.Based on the research of the compositon and the working principle of traditional PLC, we proposed a software model for embedded SoftPLC, in the time we adoptted the moular design method to convenient the functions upgrating of the embedded SoftPLC. The running system of the embedded SoftPLC was mainly consisted of the analitical module for configuaritong file,the internal variable access module,the logical operation module and the physical port access module. In the end of this paper, we designed a LED control test model to check the working of the embedded SoftPLC running system.