Which PLC component is a printed circuit board that delivers power to the modules and provides the data bus for exchanging data between modules and the CPU?

• A. Backplane
• B. Rack
• C. Interface
• D. Bus

Answer: (A)

In PLCs, the backplane is the printed circuit board that distributes power to all modules and provides the data bus that lets modules communicate with each other and with the CPU. It acts as the backbone of the rack, with modules plugging into it so they share a common power supply and a shared communication path. The rack is the physical frame that holds the backplane and modules, but the backplane itself is the actual circuit board that handles power distribution and data interconnection. An interface is a separate component or module that handles protocol bridging or device connections, not the centralized power/data backbone. A bus refers to the data pathway or channel, not the physical backplane that houses and routes those signals.