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DCS-Distributed Control System 

DCS 

A Distributed Control System (DCS) is a computerized control system for a process or factory that distributes autonomous controllers across the system. 

DCS can handle a large number of I/Os, allowing it to be used for whole plant automation. 

Please Visit: https://ieng.tech/dcs-distributed-control-system/ 

Basic difference between DCS & PLC 

o DCS handles more no's of I/Os rather than PLC. 

o PLC is faster system than DCS. 

o DCS can handles handsome quantity of I/Os so that can be used for total plant automation. Whereas PLC has own limitations so it generally used for small but for important (Safety point of view) units, like boiler automations, Make-up compressor automations Etc. 

o In the above-mentioned case these PLC’s can be get connected with the DCS with the help of soft link. Generally, this is used to make alert to both the operator. 

o As I heard the PLC used to handle the DI/DO signals so it can take fast actions. Some of the time it is used to handle few no's of AI/AO. 

o DCS & PLC’s speed depends on the scan rate of I/Os. 

o For both the system Marshalling panels, Consoles and other faculties of Ethernet Etc can be used according to the need. 

o According to the Cause and effects diagrams the System programmer assigns the control action block into the system, we can call them as memory assigning. 

The scan rate of I/Os affects the speed of DCS and PLC.  

o System Marshalling panels, Consoles, and other Ethernet capabilities can be employed as needed for both the system and the consoles.  

o The system programmer assigns the control action block into the system based on the cause-and-effect diagrams, which we can refer to as memory assignment.