Structure Analysis of Secured Applications Programming Language for Programmable Logic Controllers

Application of programmable logic controller in the sphere of industrial automation substantially simplified technological processes control. New data exchange systems and new algorithms are being developed. It leads to enormous variety of comptrollers. Each of them differs by specific set of functions, unique construction and certain control language. In this article we describe structure of PLC, that can help to choose one, and also present the structural analysis of PLC programming languages. IEC 61131-3 standard considered is to provide software developers PLC powerful tools to improve the quality of applications that includes the safety and security applications. However, this lack of standard practices check whether the designed application correspond to the requirements regarding protection.