In automation systems, which statement best describes a peripheral device?

• A. A device that processes data within a central computer.
• B. A device that stores data locally only.
• C. A device that is connected to a personal computer or building automation system controller to perform a specific function.
• D. A device that powers sensors.

Answer: (C)

In automation systems, a peripheral device is something that is connected to a central controller to perform a specific function, expanding what the controller can do. The statement describes exactly that: a device attached to a personal computer or building automation system controller to carry out a defined task. This connection to the host controller is what characterizes peripherals, whether they sense, actuate, display information, or handle data transfer. The other options misrepresent the idea—one describes the main processor that handles data inside the central unit, another focuses only on local storage, and another is about powering sensors rather than performing a distinct control function. So the best description is a device connected to a PC or controller to perform a specific function.