Development of Industrial Control Programming Environment Enhanced by Extensible Graphic Symbols

To make industrial control applications, many control flow diagrams are drawn using the domain graphic symbols. There are some well-known standards of control flow diagram, for example, IEC61131-3 programming languages for PLC, and ISA/SAMA functional diagram for process control. Although the integrated control systems that may cover both PLC and process control domains were launched, they had a typical problem that the most of programming environment were not integrated for each domain. For example, most of process control engineers have strong rejection reaction to IEC61131-3 programming. The authors solved this problem practically, studying the extensible custom symbol and the extended control flow diagram, and applying them to IEC61131-3 programming environment for the true integration