The location of a specific input or output field device is identified by the processor by means of its address.

• A. True
• B. False
• C. By its function
• D. By its label

Answer: (A)

In PLCs, every input or output point has a unique address that the processor uses to locate it. This address is defined during hardware configuration and maps directly to the device’s physical location on the I/O module or rack. The program uses that address to read the current state of an input or to drive an output. The device’s label or its function is for human readability, but the processor relies on the address to access it. For example, an input at address I0.0 and an output at address Q0.2 illustrate how the processor identifies location by address, not by name or function.