Structured Text (ST)
Text-based IEC 61131-3 language for PLC logic and algorithms.
IEC 61131-3's Pascal-like, text-based PLC language for expressions, calculations, state machines, data structures, and reusable functions. It is powerful for algorithms, while Ladder and Function Block Diagram often remain clearer for maintenance teams.
See also: IEC 61131-3 · PLC · PLCopen