Differences and connections between PLC systems and DCS systems
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What are the differences and connections between PLC systems and DCS systems? In what situations is a PLC system used? In what situations is a DCS system used?
PLCs are used for simple sequential control, while DCS is employed in most chemical processing plants. PLCs are also used when the number of control points is very small; some safety interlock systems are themselves built using PLCs.
This post was last edited by liuei on 2010-11-17 at 20:38. PLCs can process digital signals quickly, but they cannot be modified online; they are suitable for use when there are few analog control loops. DCS systems excel at handling the recording, adjustment, and online configuration of analog loops. Therefore, DCS systems are used in chemical plants, power plants, and other facilities where operations must not be stopped.