Iec 61131-3: Programming Industrial Automation ... Apr 2026

A low-level, assembly-like textual language. While it was once common, it was deprecated in recent editions of the standard in favor of higher-level options. Key Structural Elements

A graphical language modeled after electrical relay logic, widely favored by electrical engineers for its intuitive, circuit-like structure. IEC 61131-3: Programming Industrial Automation ...

The standard defines five distinct languages, categorized into graphical and textual formats: A low-level, assembly-like textual language

A graphical language that uses interconnected blocks to represent logic, making it easy to build and visualize complex control flows. Established in the early 1990s, it ended the

Beyond languages, the standard provides a rigorous software model to ensure program stability:

A graphical method for structuring sequential processes , decomposing problems into defined steps and transitions.

The IEC 61131-3 standard is the globally recognized authority for programming industrial control systems, specifically Programmable Logic Controllers (PLCs) . Established in the early 1990s, it ended the era of proprietary manufacturer languages, creating a unified framework that promotes interoperability and code reusability across different brands like Siemens, Rockwell, and Schneider Electric.