Handling Backtracking for Symbolic Testing of Embedded Software

Automated testing tools for programs written in IEC 61131-3 standard of programming languages supporting the development of PLC control software is less available. Symbolic execution is a program analysis technique that determines what inputs cause each part of a program to execute. Here, a symbolic execution framework is utilized to achieve test target coverage for control system software. The framework does not ensure optimal feasible paths after backtracking. In this paper an approach using weight calculation is utilized to overcome the drawback. The calculated weight values helps to backtrack to a node, on flipping will result in an optimal feasible path.