AiVibeRemote Terminal Unit (RTU)
A remote terminal unit is a ruggedised field device that collects measurements and status from equipment at remote sites, executes local logic and communicates with a SCADA master over long-distance links such as radio, cellular or leased lines.
An RTU combines I/O, a processor, communication ports and often battery-backed power in an enclosure suited to unattended outdoor or substation locations. It timestamps events, buffers data during communication outages and responds to polls or reports changes to the SCADA master using telemetry protocols such as DNP3, IEC 60870-5-101 and IEC 60870-5-104, or Modbus. Many RTUs also run IEC 61131-3 logic for local control.
RTUs are used in electricity substations, oil and gas wellheads and pipelines, water and wastewater pumping stations, reservoirs and rail infrastructure, where sites are far apart and may be connected only by low-bandwidth or intermittent links. Local intelligence lets a site keep operating safely if communication with the control centre is lost.
The distinction between RTUs and PLCs has narrowed: modern PLCs offer telemetry protocols and RTUs offer programmable logic. RTUs typically emphasise wide temperature ranges, low power consumption, event timestamping and store-and-forward communication. Because RTUs often sit on public or wireless networks, authentication and encryption, such as DNP3 Secure Authentication or VPN tunnels, together with IEC 62443 guidance, are important.
Key points
- Field device linking remote sites to a SCADA master station
- Uses telemetry protocols such as DNP3, IEC 60870-5-104 and Modbus
- Buffers and timestamps data during communication outages
- Common in substations, pipelines, water networks and rail
- Capabilities increasingly overlap with those of PLCs
Where AiVibe comes in
AiVibe designs and manufactures the AiAmbA AI Factory, whose edge devices and AI agents let people talk to PLC, CNC and robot controllers in plain language. Agents only propose changes, a trained operator confirms each one, and the AI Factory never replaces a machine's control or safety systems.