Which PLC language is described as a graphical dataflow language using interconnected blocks?

Which PLC language is described as a graphical dataflow language using interconnected blocks?

• A. Function Block Diagram
• B. Ladder Diagram
• C. Instruction List
• D. Structured Text

Answer: (A)

Think about how PLCs represent logic as data moving through functional units. A graphical dataflow language uses blocks that perform operations, with lines showing how data travels from one block to another. Each block has inputs and outputs, and the arrangement shows the sequence of processing as signals flow through the system. This is exactly how Function Block Diagram works: you place blocks that perform specific functions (like add, compare, timers, counters) and connect them with wires to pass data between blocks. The diagram visually represents how data is processed as it moves through the interconnected blocks. Ladder Diagram, while graphical, looks like a ladder with rungs and focuses on relay-style contacts and coils rather than data flowing between function blocks. Instruction List and Structured Text are textual languages, not graphical block diagrams, so they don’t depict dataflow through interconnected blocks.

Think about how PLCs represent logic as data moving through functional units. A graphical dataflow language uses blocks that perform operations, with lines showing how data travels from one block to another. Each block has inputs and outputs, and the arrangement shows the sequence of processing as signals flow through the system.

This is exactly how Function Block Diagram works: you place blocks that perform specific functions (like add, compare, timers, counters) and connect them with wires to pass data between blocks. The diagram visually represents how data is processed as it moves through the interconnected blocks.

Ladder Diagram, while graphical, looks like a ladder with rungs and focuses on relay-style contacts and coils rather than data flowing between function blocks. Instruction List and Structured Text are textual languages, not graphical block diagrams, so they don’t depict dataflow through interconnected blocks.