A microprocessor-powered electronic tool known as a Remote Terminal Unit/Remote Telemetry Units/Remote Telecontrol Units (RTU) is used in industrial control systems (ICS) to link different hardware components to either supervisory control and data acquisition (SCADA) or distributed control systems (DCS).

RTUs transfer information collected by sensors from input streams within control loops to an output stream which is then forwarded to centralized control within an ICS. The RTUs are capable of automatically establishing connections with either local or remote controls.