IEC 61131-3
IEC 61131-3 is an international standard that defines programming languages and software models for programmable logic controllers (PLCs) and industrial automation systems. It specifies five standardized programming languages: Ladder Diagram (LD), Function Block Diagram (FBD), Structured Text (ST), Instruction List (IL), and Sequential Function Chart (SFC), along with common elements like data types and program organization units. This standard ensures interoperability, portability, and maintainability of control software across different hardware platforms in industrial environments.
Developers should learn IEC 61131-3 when working in industrial automation, manufacturing, or process control, as it is the dominant standard for PLC programming worldwide. It is essential for creating reliable and standardized control logic for machinery, robotics, and automated systems, enabling code reuse and reducing vendor lock-in. Use cases include factory automation, building management systems, and energy distribution control.