Opportunities and challenges of static code analysis of IEC 61131-3 programs

Static code analysis techniques analyze programs by examining the source code without actually executing them. The main benefits lie in improving software quality by detecting potential defects and problematic code constructs in early development stages. Today, static code analysis is widely used and numerous tools are available for established programming languages like C/C++, Java, C# and others. However, in the domain of PLC programming, static code analysis tools are still rare. In this paper we present an approach and tool support for static code analysis of PLC programs. The paper discusses opportunities static code analysis can offer for PLC programming, it reviews techniques for static analysis, and it describes our tool that implements a rule-based analysis approach for IEC 61131-3 programs.