What is a DCS and what are its functions?

DCS (Distributed Control System) is an integrated control platform for industrial process control. Functions include: regulatory control (PID loops), sequence control (batch operations), data acquisition and historization, alarm management, operator interface (HMI), engineering configuration, and reporting. Distributed refers to control functions distributed across multiple controllers for reliability. Modern DCS integrates with safety systems, asset management, and higher-level systems. Major vendors: Honeywell, Emerson, ABB, Yokogawa, Siemens.