In PLR programming, 'FBD' designates:

In PLR programming, 'FBD' designates:

• A. Function Block Diagram
• B. First Block Done
• C. Follow-up Being Done
• D. Free By Design

Answer: (A)

Function Block Diagram is a graphical language used in PLC programming (IEC 61131-3). In FBD, you model logic by placing function blocks (each block performs a specific operation, like AND, OR, timers, counters, or custom functions) and connecting them with data lines that carry signals between blocks. This block-and-connection style makes it easy to visualize how data flows through the system and how different functions combine to produce the final control action. That’s why the designation is Function Block Diagram: it’s the standard term for this type of PLC programming representation. The other phrases don’t correspond to established PLC terminology.

Function Block Diagram is a graphical language used in PLC programming (IEC 61131-3). In FBD, you model logic by placing function blocks (each block performs a specific operation, like AND, OR, timers, counters, or custom functions) and connecting them with data lines that carry signals between blocks. This block-and-connection style makes it easy to visualize how data flows through the system and how different functions combine to produce the final control action.

That’s why the designation is Function Block Diagram: it’s the standard term for this type of PLC programming representation. The other phrases don’t correspond to established PLC terminology.