What is Function Block Diagram?

Function Block Diagram (FBD) is a graphical programming language used in programmable logic controllers (PLCs). It is one of the five languages defined by the IEC 61131-3 standard for PLC programming. FBD uses blocks representing functions or function blocks that are interconnected to define the logic of a control system. These blocks can represent basic operations (e.g., AND, OR, NOT), timers, counters, or more complex functions. Data flows between blocks via connection lines, allowing for the visual representation and implementation of complex control algorithms. FBD is commonly used in industrial automation for process control, machine control, and other applications where a graphical representation of the control logic is beneficial for design, understanding, and maintenance.