Field devices are identified by the processor by means of their addresses.

• A. True
• B. False
• C. By their labels
• D. By their color

Answer: (A)

Field devices are identified by addresses because the PLC uses a defined I/O map that assigns each physical device a unique address. The CPU reads inputs and writes outputs by these addresses, so the exact location in the I/O map tells the processor which device is involved. Labels and colors are just human-friendly ways to document and understand the wiring, but they don’t determine how the processor locates or communicates with the device. The addresses (like a specific input or output address) are what the program and the processor rely on to identify field devices. So the statement is correct.