Which technology links different programmable logic controllers together?

Which technology links different programmable logic controllers together?

• A. CAN
• B. Modbus
• C. Fieldbus
• D. PLC

Answer: (C)

In industrial automation, linking several PLCs relies on a fieldbus—the networking technology that acts as the real-time backbone for interconnecting controllers and field devices. Fieldbus provides a shared medium and standardized communication to move data between PLCs, sensors, and actuators, enabling coordinated, distributed control across the system. This is the right choice because it directly refers to the industrial network that ties multiple PLCs together. A controller area network (CAN) is a robust bus used mainly in automotive and some embedded systems, not the standard structure for plant-wide PLC interconnection. Modbus is a communication protocol that can run over various physical layers, but it describes how messages are formatted rather than the complete linking technology. A PLC is the controller itself, not the network that connects multiple controllers.

In industrial automation, linking several PLCs relies on a fieldbus—the networking technology that acts as the real-time backbone for interconnecting controllers and field devices. Fieldbus provides a shared medium and standardized communication to move data between PLCs, sensors, and actuators, enabling coordinated, distributed control across the system.

This is the right choice because it directly refers to the industrial network that ties multiple PLCs together. A controller area network (CAN) is a robust bus used mainly in automotive and some embedded systems, not the standard structure for plant-wide PLC interconnection. Modbus is a communication protocol that can run over various physical layers, but it describes how messages are formatted rather than the complete linking technology. A PLC is the controller itself, not the network that connects multiple controllers.