Glossary · HMI, SCADA and operations
Supervisory control and data acquisition (SCADA)
Also known as: SCADA, SCADA system
German: Prozessleitsystem (SCADA)
In industrial automation, supervisory control and data acquisition (SCADA) is a system architecture for supervising and controlling distributed equipment, in which central servers collect data from PLCs and remote terminal units, present it to operators and send supervisory commands, while local controllers perform the real-time control.
- HMI and SCADA
- OT security
In one sentence
SCADA supervises distributed equipment: central servers collect data from PLCs and RTUs, show it to operators and send commands.
Example
A pipeline operator uses SCADA to monitor pressures and flows at compressor stations hundreds of kilometers apart and to open or close remote valves.
How it applies
- Engineering: SCADA is typical for utilities, pipelines, infrastructure and manufacturing lines with many PLCs. Communication may run over wide-area networks with protocols such as IEC 60870-5-104, DNP3, Modbus or OPC UA.
- Security: SCADA systems are frequent targets of cyberattacks. Segmentation, secure remote access and monitoring according to IEC 62443 are central, and critical-infrastructure rules may apply.
- Operation: Because real-time control stays local, the plant should continue in a defined way if SCADA communication fails. Define and test this behavior.
- Documentation: Document the architecture, communication paths, failure behavior, user roles and alarm handling. Operator manuals should explain what the operator sees when a remote station loses communication.
SCADA vs. DCS
SCADA supervises geographically distributed equipment controlled by PLCs or RTUs. A Distributed control system (DCS) integrates control and supervision in one system for a process plant. The German list term "Prozessleitsystem" is used for both, so clarify in translations.