Since in many applications in industrial control systems the operating terminal cannot be located directly next to a control device, a computer or a control station, in such cases a remote terminal unit (RTU), also known as a telecontrol station, is used.
The use of a remote terminal unit is recommended when the area of operation is at risk or when an operator terminal cannot be accommodated for reasons of space or distance. Such RTU units are also found in telemetry where control systems are physically separated from substations.
Remote terminals are directly connected to the master station and control and monitor the substations from its certain distance. The measured values are displayed in real time on the RTU units. Remote control terminals can be used to detect and analyze faults. In addition, networked RTU units can communicate with each other, facilitating fault analysis.
RTU units are used in many industries, industrial sectors and processes, with applications in industrial control systems( ICS) to connect different hardware to process control systems( DCS). Furthermore, Remote Terminal Units are used in the petrochemical industry, in chemical plants, power plants and nuclear power plants, in the wood and metal processing industry, the automotive industry, food production, water treatment and many other industries.