What is SCADA?
SCADA stands for Supervisory Control And Data Acquisition. It is a software system used to monitor, visualise and remotely control industrial processes. SCADA plays an essential role in production environments, infrastructure and process industries, where real-time Monitoring and rapid response to deviations are critical.
🧠 What does SCADA do?
A SCADA system:
- Collects real-time data from devices such as sensors, motors, valves and pumps
- Presents the data visually to operators through graphical screens (HMIs)
- Provides operating capabilities to control processes (e.g. start/stop of machines)
- Stores historical data for trending, analysis, reporting and troubleshooting
- Sends notifications or alarms when process deviations occur
🔄 Relationship with PLC
A SCADA system itself usually does not directly drive physical equipment. Instead, it communicates with a PLC (Programmable Logic Controller), which in turn controls the equipment on the shop floor. The PLC reads field signals and executes logic, after which SCADA collects and visualises that data. These communication variables are called Tags.
🔁 SCADA monitors and controls processes through the PLC, which performs the actual control.
🏭 Example applications
- Monitoring a drinking water treatment plant
- Real-time monitoring of an electricity grid
- Controlling HVAC systems in large buildings
- Managing production lines in factories
📌 In summary
SCADA is the visual brain of industrial automation. It enables operators to follow, analyse and adjust processes where necessary — based on data coming from a PLC.