A distributed control system (DCS) is a type of control system used in industrial automation to control and monitor a process. It typically includes a central control unit, called a controller, which is connected to various field devices, such as sensors and actuators, that are used to collect data and control the process.
SCADA (supervisory control and data acquisition) is a type of industrial automation system used to monitor and control industrial processes, often remotely. It typically includes SCADA software in a central computer system to collect and process data from various field devices, such as sensors and actuators. SCADA system information is displayed on a human-machine interface (HMI) for operators to view, monitor and help make decisions about controlling the process.
In SCADA systems, DCSs are often used as the control system in the field for control of the process and communication with the field devices. The SCADA system, on the other hand, provides the supervisory level and human-machine interface, and provides the higher-level control and monitoring of the process.
In summary, DCS is a type of control system that is used to control and monitor industrial processes, while SCADA is a type of industrial automation system that is used to monitor and control industrial processes, often remotely. DCSs are often used as the control system in the field, while the SCADA system provides the supervisory level and human-machine interface.