Industrial controllers are used in many modern systems, such as DCS systems to interface with enterprise systems so that the production process can be reflected in the overall operation of the business. DCS systems are commonly used in industrial control areas such as oil refineries, wastewater treatment plants, chemical plants and pharmaceutical factories. This article focuses on the basic structure and types of industrial controller systems.
1, distributed control system (DCS)
Industrial controller DCS uses centralized monitoring to coordinate local controllers to perform the entire production process. By modularizing the production system, DCS reduces the impact of individual failures on the entire system. In many modern systems, DCS systems and enterprise systems set up interfaces between so that the production process can be reflected in the overall operation of the business.
2, data acquisition and monitoring system (SCADA)
SCADA (SupervisoryControlAndDataAcquisition) system is used to control and manage geographically distributed assets (assets), these assets are generally dispersed over thousands of square kilometers. Central data acquisition and centralized control of industrial processes is very important to the operation of the entire system, SCADA systems are usually used in similar water supply projects, sewage systems and natural gas pipeline networks. sCADA control centers centrally monitor and control the field node equipment in the remote communication network, including alarm information and process status data, etc.. The central control center relies on information obtained from the remote site to generate automated or process-driven monitoring commands and send them to the remote site to achieve real-time control of the remote device, which is a field device in the industrial field. Field device operation is similar to the opening/closing of valves and circuit breakers, sensor data acquisition and site environmental monitoring alarms and other local operations.
3, industrial controllers in the programmable logic controller (PLC)
PLC is based on the traditional sequence controller introduced microelectronics technology, computer technology, automatic control technology and communications technology and the formation of the second generation of new industrial control devices. The International Electrotechnical Commission (IEC) promulgated the provisions of the PLC: programmable controller is a digital algorithmic operation of electronic systems, designed for application in industrial environments. It uses a programmable memory, which is used to store instructions for performing logical and arithmetic operations within it, and to control various types of machinery or production processes. Programmable controllers and their related equipment should be designed according to the principle of easy to form a whole with the industrial control system and easy to expand its functions.PLC is widely used in almost all industrial production processes, and it is one of the key components in SCADA system or DCS control system.
On the subject of industrial controllers, this paper focuses on the basic structure and types of industrial controller systems. Different types of industrial controllers have different characteristics, so they should be selected according to the situation when they are specifically used.