Design And Implementation Of IL Language Compiler Based On IEC61131-3 Standard

Since the International Electrotechnical Commission officially released the IEC61131-standard, the major domestic and foreign automation manufacturers have introduced several related configuration software based on this standard. The standard clearly defines the programming language specification used in industrial automation control systems. It aims to facilitate the code migration and program reuse. It also can reduce the customers’use difficulty and cost. Instruction List language is one of five programming languages in the standard. IL language is the most basic programming language, because other programming languages can be easily converted to IL language. Configuration software, as the PC software in the control systems such as DCS, PLC and so on, plays an important role in the whole system. The compiler is the core module in the configuration software, and its performance has a great influence on the operation efficiency of the entire control system.This paper first outlines the content of the IEC61131-3 standard and the grammar rules of IL language, and then introduces the theory of compiling principles and the design plan of IL compiler. This paper makes analysis of programming language and configuration software, and gets the requirements of the compiler. Then it gives a description of the overall architecture of the compiler, and it proposed the compiler’s detailed implementations on this base. According to the overall design plan, the entire compilation is divided into different modules to implement. Firstly, it uses FLEX and BISON auxiliary generation tools during the lexical analysis and syntax parsing period. It completes the lexical document and syntax document according to the relevant Instruction List language grammar rules. Secondly, it presents an intermediate code structure according to the results of semantic analysis and the compiler front-end and back-end features, which is independent of the target platform and is simple to facilitate subsequent optimization. Thirdly, it designs the auxiliary module to maintain the normal operation of the entire compiler system. The auxiliary module includes run-time environment and error management two parts. Finally, it chooses an ARM controller as the target platform, and fulfills the instruction selection and instruction encoding, which is the main part of the target code generation module. This paper is associated with the actual development projects, combined with the previous work 1 had done. Besides, it adds some new data structure and does some optimization. On these basis, it realizes a complete IL compiler.