Algorithm and tool for LD to SFC conversion with state-space method

Still to this day, there are many industrial sequential processes described in Ladder Diagram (LD), a language not suitable for that purpose, that can be described in SFC, a proper language for describing sequential processes. We provide analysis on the main algorithms for extracting the sequential logic from a LD program that can be found in the literature and point some problems in them. We then propose a new algorithm to extract the sequential logic and produce a state-machine from a LD program. We describe a tool developed to implement said algorithm and show the results.