Supervisory control and data acquisition (SCADA) systems are centralized control systems that monitor, collect and process data from sensors placed throughout a factory or remote field location.
SCADA systems are used in a variety of industries such as traffic systems, electric power utilities and mass transit systems where equipment functions must be closely monitored and controlled automatically. SCADA systems can collect data from sensors as well as send control signals back to the equipment being monitored.
SCADA systems perform several functions. The three basic functions are the monitoring, control and user interface functions. The monitoring function collects data and sends it back to the central computer. The control function gathers data from monitoring sensors, processes it and send control signals back to the equipment according to a prescribed software program. The user interface is often a large control room where individuals can monitor SCADA input and output responses in real time.
A large-scale application of a SCADA system is a nuclear power plant where thousands of sensors monitor mission-critical and safety-critical systems. The computer system collects data from the sensors, processes updates and makes computer-controlled adjustments to equipment as required to maintain operational and safety parameters. In addition to the automatic controls, employees staff a large control room where they monitor the entire system around the clock.