Each piece of HVAC equipment controlled through building automation has its own?

• A. gateway
• B. HMI
• C. PLC
• D. control transformer

Answer: (C)

The main idea is that each HVAC device in a building automation system needs its own controller to run its specific control logic. A programmable logic controller is designed to take inputs from sensors, apply the programmed sequencing and safety logic, and drive the appropriate outputs to the equipment. This setup allows each piece of equipment to operate correctly on its own or as part of a coordinated system, while still being independently controllable and monitorable within the BAS.

A gateway is used to translate and bridge different network protocols, not to control the device directly. An HMI is the human interface for operators to view status and issue commands, not the device’s control logic. A control transformer provides the necessary low-voltage power for control circuits, but it does not perform control functions.