1. Industrial control system definition

Industrial Control Systems (ICS) is a business process control system composed of various automatic control components and real-time data acquisition and monitoring process control components to ensure the automatic operation of industrial infrastructure, process control and monitoring. Its core components include Supervisory Control and Data Acquisition (SCADA) and Distributed Control Systems,DCS), Programmable Logic Controller (PLC), Remote Terminal Unit (RTU), Human Machine Interface,HMI), and the interface technology that ensures communication between components.

A SCADA control center is a communications network that provides centralized monitoring of the site over a long period of time, including monitoring alarms and processing status data. Automated or operator driven monitoring commands can be pushed to remote station control devices, often referred to as field devices. Field equipment controls local operations such as opening and closing valves and circuit breakers, collects data from sensor systems, and monitors alarm conditions in the local environment.

DCS is integrated as a control architecture, containing supervisory level control that oversees multiple integration subsystems that are responsible for controlling the details of the localization process. DCS is used to control industrial processes such as power generation, oil and gas refining, water and wastewater treatment, and chemical, food and automotive production.

PLC is a computer-based solid state device used to control industrial equipment and processes. PLCS are the control system components used throughout SCADA and DCS systems, and they are usually the main components in smaller control system configurations used to provide regulatory control of discrete processes such as automotive assembly lines and power plant soot blower control. PLC is widely used in almost all industrial processes.

HMI is the display screen in front of the operator. After the configuration of HMI and plc, PLC communication control can be achieved through HMI to control the terminal equipment.

2. Communication protocols in industrial control

There are many public and private agreements that can be divided into the following categories:

Standard protocol: international standard or recognized standard protocol, such as Modbus, DNP3, IEC104, etc

Private disclosure: Only vendor devices support and provide official agreement documentation such as Omron FINS Agreement, Mitsubishi Melsec Agreement, etc

Private but not public: Only the device supported by the manufacturer does not provide official protocol documents, such as S7, Siemens PPI, and GE SRTP