What is a DCS or SCADA network?
DCS are used to control large, complex processes such as power plants, refineries, and chemical plants typically, but not always, at a single site. A DCS is comprised of a supervisory layer of control and one or more distributed controllers contained within the same processing plant. The supervisory controller runs on a central server and communicates with subordinate controllers via some form of peer-to-peer network. The supervisor sends set points to and requests data from the distributed controllers. The distributed controllers control their process actuators (switches, valves, flow controllers, etc) based on requests from the supervisor. These controllers typically use a local field bus to communicate with the actuators and sensors eliminating the need for point-to-point wiring to each device. Many times, the distributed controllers in a DCS have the capability to be accessed via a modem allowing remote diagnostics and servicing by vendors and plant engineers. A SCADA network typic
