A remote terminal unit (RTU) is a microprocessor-controlled electronic device that interfaces objects in the physical world to a distributed control system. A remote terminal unit (RTU) is a multipurpose device used for remote monitoring and control of various devices and systems for automation. It is typically deployed in an industrial environment and serves a similar purpose to programmable logic circuits (PLCs) but to a higher degree.

RTUs pass sensor data from input streams in control loops to an output stream to be forwarded on to centralized control in an ICS. RTUs automatically negotiate connections to either local or remote controls.