Research And Realization On Compiling System Of Construction Machinery Embedded PLC

Compiling system is the key to develop the embedded PLC, which lays a great effect on the executing performance of embedded PLC. Most PLC compiling systems are closed, expensive and possess the property rights protection in the market at present. This paper intends to research and realize PLC compiling system independently.The advantages and disadvantages of traditional PLC compiling system were analyzed, combining the new idea in the field of compiling in recent years. Eventually the method of PLC instantaneous compiling by combination of compilation and interpretation was put forward, which solves the contradiction between resource consumption and running speed in the upper machine and lower machine by traditional compiling system, and achieves the effective balance between industrial control requirements and software development. In order to solve the problem of large workload on compiling system, the method of explaining backend was put forward to simplify the phase of compiling target code of system and lower the workload of compiling system sharply. Taking the problem of grammar and semantic equivalence transformation of PLC complexly, the method of the intermediate language was put forward to express any semantic PLC source language contained adequately. Meanwhile means of downsizing PLC source language instruction set was put forward to ease the pressure on the underlying processing commands, improving the efficiency of the underlying explanation to transplant, modification, optimization easily. With the strict requirements of accuracy on compiling system, a perfect mechanism of error handling was established to find mistake of source program accurately, ensuring that users can locate the error accurately and modify conveniently. Considering the heterogeneity of target architecture, GCC backend was configured to obtain explain backend of specific models. Considering demand of construction machinery, reliable symbol table was established and maintained to satisfy the requirement of the industrial port and other characteristics.Taking the construction machinery controller of Sunward Company as platform, based on PC Windows system and VS2005development environment, using C++development language, the front compiler and the upper interpreter of the compiling system was realized.By configuring the GCC back-end, the transplant from the upper interpreter of compiling system to the target machine which has PowerPC architecture was done. In the end, a mini PLC compiling system was implemented, which provides a compilation environment for PLC integrated development environment on the upper machine.