RTU
Remote Terminal Unit - a device that collects data from field sensors and transmits it to a SCADA system via telecommunications links.
What is an RTU?
An RTU (Remote Terminal Unit) is an electronic device installed at remote locations within industrial infrastructure. Its purpose is to collect data from local sensors and measurement devices, perform preliminary data processing and transmit it to the central SCADA system. The RTU can also receive control commands from the supervisory system and execute them locally.
RTUs are used wherever facilities are geographically dispersed: in power grids (transformer substations), water networks (pumping stations), gas networks (pressure reduction stations) and telecommunications. They communicate with the central system via various media - radio links, GSM/LTE, satellite links or fibre optics.
Modern RTUs combine the functions of a traditional telemetry unit with PLC capabilities, offering local control logic processing. This allows them to autonomously control a process even if communication with the central system is lost.
Why does it matter?
RTUs are often installed in locations that are difficult to access physically - on power poles, in roadside cabinets, at remote pumping stations. This makes both physical protection of the devices and regular software updates challenging. Many RTUs communicate using protocols without built-in authentication or encryption (Modbus, DNP3).
Securing RTUs requires communication encryption, network segmentation, monitoring of telemetry traffic for anomalies and physical protection of devices against unauthorised access.
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