what is distributed control system? what is the differences between the process using liquid and gases? thx in

Answer 1

A distributed control system is one in which control actions are taken locally by equipment that has sensors, logic, and actuators. If there is a problem it is handled right there. A centralized system is one in which every one of the sensors from every piece of the process are brought into a huge computer. That computer runs all of the logic for everything in the plant. Then it adjusts every actuator by using its many outputs.

An example would be if there were two water pumps that could fill the same fire system water tank. Each could have its own water level sensor, its own level control logic, and its own adjustable speed control for a pump. That would be distributed. If instead both sensors and both speed controllers were tied to a central large computer that would be centralized control.

Distributed systems tend to be more economical since each is a smaller unit. They tend to be more robust since if one goes down there is probably a second unit that could be used instead of the one giant computer going down and nothing is working.