What is the difference between DCS system and PLC control system?

1. What is the difference between DCS system and PLC control system?

DCS tends to control a large number of circuits and is widely used in large-scale control in the process industry, characterized by a large processing capacity.

PLC was developed from relay circuits, while DCS was developed from local instrument screens.

With the development of electronic circuits, the interfaces of DCS and PLC control systems are becoming increasingly unclear. Ordinary control cabinet and PLC control cabinet.

2. What is the difference between DCS and PLC

PLC: Programmable Logic Controller.

2. DCS focuses more on the field of process control (such as chemical, metallurgical, pharmaceutical, etc.), mainly monitoring and controlling some on-site parameters, while PLC focuses on logic control (mechanical processing). Of course, PLC process control problems can also be handled well now, but there is no DCS specialty.

3. For analog quantities greater than points, DCS is generally used; For analog quantities within points, PLC is generally used.

4. DCS is a decentralized control system. PLC is just a control device, and the two are the differences between systems and devices. This system can achieve the functions and coordination of any device, while the PLC device only implements the functions of this unit.

5. The DCS network is the central nervous system of the entire system, and the DCS system usually uses the international standard protocol TCP/IP. It is a secure and reliable dual redundant high-speed communication network with better scalability and openness. PLC, because it mainly works for a single small system, when communicating with others on PLC or upper computer, the network form used is mostly a single network structure, and the network protocol often does not comply with international standards. Does the PLC control cabinet belong to an electrical cabinet.

6. All I/O modules in the DCS system are equipped with CPUs, which can achieve quality judgment and scalar transformation of collected and output signals. If there is a fault, they can be unplugged and replaced randomly. The PLC module is only a simple electrical conversion element without intelligent chips, and all corresponding units will be paralyzed after a fault occurs. Temperature control system PLC.