Composition and functions of DCS system
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I would like to ask about the functions of the various components of a DCS system. I hope you can be more detailed. Sensor — Signal transmission — Analysis and command issuance system — Signal transmission — Actuator. Is this the correct way to understand it? I went to a factory for an internship over the summer, and in the control room I saw several very large cabinets. What’s inside those cabinets? PLC? And what about the latest FCS system? Thank you so much!
What the original poster is talking about is a very basic control loop. Those cabinets are part of a DCS; they are generally referred to as field control stations. They could also be PLC control cabinets. To understand more about DCS and PLCs, it’s necessary to consult specialized materials – it’s impossible to explain everything in just a few sentences, haha
Field instruments (sensors, transmitters) — cables — control system (the cabinets you see) — cables — actuators such as valves. Control systems include DCS or PLC, etc., referring to the modules in the cabinet. The module contains a control module, which serves as the brain of the control system and functions like a microprocessor. The control station computer is connected to it and exchanges information with the control system; there is also a computer in the system called a server, which takes on some of the processing tasks. Control systems from different brands differ in terms of the control modules and software installed on the computers.
DCS is a hierarchical structure, generally divided into: the plant-wide management level, the process management level, the process control level, and the field control level. The actual composition and functions of a factory’s DCS are as follows: Field instruments typically consist of sensors and control valves; the sensors send signals to the control room (operator station) as well as to the DCS cabinet, which contains power supplies, cards, an emergency stop system, and safety barriers. The cards contain control algorithms, which in turn generate signals to control the field control valves. The process management level serves a monitoring function, while the overall factory management level conducts comprehensive analysis of information related to production and sales across the entire factory, and then formulates production plans.
I’ve learned it, but are there any detailed materials available for us beginners to continue learning?