IEC 61131-3 is the third part of the open international standard IEC 61131. It defines programming languages, both textual and graphical, for Programmable Logic Controllers (PLC). The Sequential Function Chart (SFC) is a graphical language for organizing programs for sequential and parallel control processing.
In my undergraduate thesis, I developed a Windows software that implements the SFC language as defined in IEC 61131-3. The software runs on Distributed Control Systems (DCS), where controllers and engineering stations are connected via a communication network (e.g. Ethernet). It consists of three main components:
System configuration in VET (in the main table are the input/output and memory variables)
Visual editing of SFC charts (drag-and-drop, double-click for configuration dialog)
Monitoring and debugging SFC charts in VET (the green block is the current step)
Running with chemical reactor simulator
This software is not in public domain. If you want to ask questions about it, or if you want to use it for education, feel free to contact me.