A Supervisory Control and Data Acquisition System (SCADA) is a computer hardware and software solution that automates industrial processes without human intervention. It works by collecting real-time data remotely, then processing the data and controlling related equipment. Engineers use SCADA systems to remotely or locally control industrial processes and collect, monitor and process data in real time. SCADA systems also enable staff to directly control and manage equipment such as valves, sensors, motors, pumps, etc. using human-machine interface (HMI) software.
SCADA systems are popular in various industries, including new energy and power, manufacturing, oil and gas, water and wastewater treatment, and transportation. Almost every industrialized or operation-intensive industry requires a proprietary SCADA system solution to keep running smoothly.
Composition of SCADA Systems
SCADA systems are composed of hardware systems and software systems. The SCADA hardware system contains a client layer and a data server layer. The client layer implements human-computer interaction, and the data server layer processes and manages data. SCADA software systems usually consist of software for graphical display of process data, diagnostic information, and data management.
What are the types of SCADA systems?
- Monolithic SCADA systems
Monolithic SCADA systems rely on large microcomputers for processing and are stand-alone systems that are not interconnected to the network.
- Distributed SCADA systems
In a distributed SCADA system, information and command processing is decentralized and occurs between sites connected using a LAN, which allows real-time data sharing. Each task is assigned a dedicated station, which helps reduce costs compared to monolithic SCADA.
- Web SCADA systems
Finally, web-based SCADA systems enable users to view and exchange data and control processes over the network. Web SCADA systems typically use an Internet browser as a graphical user interface (GUI), and users can access the system from a client or mobile terminal.
Components of SCADA System
- Master Terminal Unit
The Master Terminal Unit (MTU) acts as a central communication server. It is located in the control center and manages the information exchange between the human-machine interface and RTU, sensors, PLC and other devices.
- Remote Terminal Unit
The remote terminal unit (RTU) is an electronic device used for remote acquisition and control. The RTU device is connected to wireless transmitters, sensors, monitors and other devices at remote sites. The RTU collects data and transmits it to the control center, where it is monitored and processed.
- Programmable Logic Controller
The programmable logic controller (PLC) is a device that can replace the RTU to control the system. The PLC is connected to the sensor and can convert the sensor data into digital signals.
- Human-machine interface
The human-machine interface (HMI) usually displays information in the form of graphics of the SCADA system for staff to view and control. Staff can use the HMI to access the control unit.
- Electronic equipment
Electronic equipment includes microprocessor-based controllers, relays, etc., which can communicate with other devices within the SCADA system.
- Network Server
The network server can monitor the network hardware and software of the SCADA system, and performs functions including device monitoring, performance analysis, device discovery and management, and alarm and data analysis.
- Communication Component
The SCADA system exchanges data through wireless, wired and Internet connections.
Characteristics of SCADA
- High real-time performance: SCADA systems ensure production safety by providing real-time information on the status of all equipment and workflows.
- High efficiency: SCADA systems can greatly improve production efficiency and reduce labor costs in the manufacturing industry.
- High cost: SCADA deployment is expensive and usually requires dedicated hardware, customized software, and training for human operators for daily use and regular maintenance.
- Complexity: SCADA systems are complex to use, and SCADA system deployment requires professional knowledge of staff