Toward Standardizing Configuration

An international standard has been established that, for the first time, offers the promise of resolving the proliferation of configuration techniques that have buried the users of control systems. The IEC (International Electrotechnical Commission) was established in 1906 to facilitate the coordination and unification of standards among member nations focusing on electrical and electronic products. The IEC 61131-3 standard defines two graphical languages, two text-based languages, and a fifth-language invented to provide a high-level of syntax. The two graphical languages are ladder diagram, a typical programmable controller (continuous or sequential) language, and function block diagram, a mostly continuous execution model (PID, math, continuous control). The two text-based languages are instruction list, a low level (like assembler or machine code) language, and structured text, a Pascal-like program language. The fifth language was invented to provide a high-level syntax called sequential function charts.