DCS is short for Distributed Control System, commonly referred to as a centralized control system in China. It is a multi-level computer system comprised of process control and process monitoring levels linked by a communication network. It integrates 4C technologies: Computer, Communication, Display (CRT), and Control. Its basic principles are distributed control, centralized operation, hierarchical management, flexible configuration, and convenient setup. DCS has the following characteristics:
1. High reliability
Because DCS distributes system control functions across various computers and employs a fault-tolerant design, a failure in one computer will not lead to the loss of other system functions. Furthermore, since each computer in the system performs a relatively singular task, dedicated computers with specific architectures and software can be used for the required functions, thereby improving the reliability of each computer in the system.
2. Openness
DCS adopts an open, standardized, modular, and serialized design. The computers in the system communicate with each other via a local area network to achieve information transmission. When it is necessary to change or expand the system functions, the new computer can be easily connected to the system communication network or removed from the network, with almost no impact on the operation of other computers in the system.
3. Flexibility
By configuring hardware and software according to different process application objects through configuration software, the measurement and control signals and their interconnections are determined, the applicable control laws are selected from the control algorithm library, and the basic graphics are called from the graphics library to form the various monitoring and alarm screens required, thereby conveniently constructing the required control system.
4. Easy to maintain
Small or micro dedicated computers with single functions are characterized by simple and convenient maintenance. When a part or a computer fails, it can be replaced online without affecting the operation of the entire system, and the fault can be quickly eliminated.
5. Coordination
Various data are transmitted between workstations through a communication network, enabling information sharing and coordinated work across the entire system to complete the overall functions and optimization of the control system.
6. Comprehensive control functions
It has a rich set of control algorithms, integrating continuous control, sequential control and batch control. It can realize advanced control such as cascade, feedforward, decoupling, adaptive and predictive control, and can easily add special control algorithms as needed.
DCS (Distributed Control Systems) are highly flexible in their configuration. They can consist of dedicated management computer stations, operator stations, engineer stations, recording stations, field control stations, and data acquisition stations, or they can be composed of general-purpose servers, industrial control computers, and programmable logic controllers (PLCs). They adopt a basic design philosophy of distributed control and centralized operation and management, employing a multi-tiered, hierarchical, and cooperative autonomous structure. Their main characteristics are centralized management and distributed control. DCS has been widely applied in various industries, including power, metallurgy, and petrochemicals.
