DCS

A distributed control system (DCS) is a specially designed automated control system that consists of geographically distributed control elements over the plant or control area.

It differs from the centralized control system wherein a single controller at central location handles the control function, but in DCS each process element or machine or group of machines is controlled by a dedicated controller. DCS consists of a large number of local controllers in various sections of plant control area and are connected via a high speed communication network. These controllers able to communicate among themselves and also with other controllers like supervisory terminals, operator terminals, historians, etc. Different field buses or standard communication protocols are used for establishing the communication between the controllers. Some of these include Profibus, HART, arc net, Modbus, etc.