Which term refers to external devices that are turned on and off by a PLC, such as a motor or valve?

Which term refers to external devices that are turned on and off by a PLC, such as a motor or valve?

• A. Inputs
• B. Outputs
• C. Tags
• D. Relays

Answer: (B)

External devices that the PLC turns on and off are called outputs. The PLC reads signals from sensors and other inputs, then drives actuators like motors and valves through its output points. A motor or valve is an actuator, meaning it performs action when the PLC provides the control signal. Tags are simply names used in the program to reference I/O points, not the devices themselves. Relays are hardware switches that can be used in the circuit, but the general category for devices controlled by a PLC is outputs.

External devices that the PLC turns on and off are called outputs. The PLC reads signals from sensors and other inputs, then drives actuators like motors and valves through its output points. A motor or valve is an actuator, meaning it performs action when the PLC provides the control signal. Tags are simply names used in the program to reference I/O points, not the devices themselves. Relays are hardware switches that can be used in the circuit, but the general category for devices controlled by a PLC is outputs.