Tutorial on SCADA basics
SCADA stands for Supervisory Control And Data Acquisition. It refers to type of industrial control system used to monitor and control various processes and operations, such as power generation, manufacturing, water treatment, oil and gas pipelines and more. SCADA systems provide real time data, visualization and control capabilities. It is used by engineers and operators responsible to manage and optimize various complex processes.
Key features of SCADA system include data acquisition, supervision, control, alarm and event management and data logging. It uses various communication protocols to gather data from sensors and control devices. Let us understand how SCADA works.
SCADA working principle
SCADA system involves collection, monitoring, control and management of data from various sensors and remote devices. It helps engineers to make informed decisions and take appropriate actions. Following are the system components of a typical SCADA system. Let us understand functions of each.
Data acquisition using sensors - Data is gathered from sensors, instruments and devices
installed throughout the industrial process. The sensors measure various parameters such as
temperature, pressure, flow rate, current, motion and more.
The data acquisition involves either polling or communication with the devices.
The sensors are attached with RTUs to conduct measurements of various parameters.
SCADA Remote Telemetry Units (RTUs) : These units are interfaced with sensors as well as with SCADA
master using communication network. They deliver various parameters to the central station (i.e. SCADA master).
SCADA Master : It is composed of various programmable controls, multiprotocol support and provides human interface.
It takes inputs from sensors via RTUs and regulate various applications.
Provides various display formats in graphs, tabular and other forms.
It will have different kinds of LEDs/Alarms for various functions.
It provides email/paging based on certain conditions.
Communication medium/network :
These are various interfaces to connect SCADA master with SCADA RTUs.
SCADA uses wired (Ethernet, serial) or wireless (RF or cellular network) protocols.
Some of the popular protocols are Modbus, OPC, DNP3 and others to collect the data from sensors or devices.
The collected data are transmitted to central SCADA server for processing.
Data processing and visualization : The collected data are processed and organized by SCADA software.
GUI of software provides real time visualizations, alarms, charts and other relevant information to
operators and engineers.
Alarms, Notifications and supervision : It monitors data against set threshold and genarates alarms and notifications as
required. Operators can control and supervise industrial processes remotely.
Data logging, reporting and analysis : The data can be stored in databases for further analysis and reporting.
SCADA systems use various tools for this purpose.
Security and remote access : The system allows authorized personnel to access and control the system
remotely.
SCADA System manufacturers
Following table lists SCADA system providers and their associated equipment manufacturers.
| SCADA Company | Description |
|---|---|
| ABB | The company offers SCADA solutions (such as ABB AbilityTM) which is used for various industries including oil and gas, power generation and more. The company manufactures SCADA equipments including PLCs (programmable logic controllers) , RTUs (Remote Terminal Units) and other communication devices. |
| Siemens | Offers SCADA solutions under SIMATIC brand, produces PLCs, RTUs and HMIs (Human Machine Interfaces). |
| Schneider Electric | The company provides SCADA solutions under Wonderware brand including PLCs/RTUs and other devices. |
| Rockwell Automation | Offers solutions in their specific brand in addition to SCADA equipments listed above. |
| GE Digital | -Sama as above- |
The other SCADA companies are Honeywell, Emerson, AVEVA, YOKOGAWA, Phoenix contact, B&R automation and so on.
SCADA Applications
SCADA has following major applications of use.
Electric Utilities- Manage Current,voltage, circuit breaker, power grid.
Water and Sewage - Monitor and control water level, water flow and water pipe pressure.
Building - Control heating, ventilation, air conditioning, visualization, lighting and building access systems.
Mass Transit - regulation of electricity, track and locate buses, trams, trains
Railways/Roadways - Control traffic signal lights
Oil and Gas : Real time monitoring of pipeline operations including flow, pressure, leak detection etc.
for safe and efficient transportation of oil and gas.
pharmaceutical & Healthcare : Monitoring and control of critical processes in pharmaceutical
manufacturing to ensure product quality and compliance.
Environmental monitoring : Continuous monitoring of air and water quality, emissions and pollution levels.
Agriculture and Farming : Monitoring of soil moisture, temperature and other parameters for crop management.
Conclusion : SCADA systems provide significant benefits across wide range of industries. SCADA facilitates real-time data monitoring, control and analysis. SCADA contributes to improved operational efficiency, reduced downtime, enhanced safety and so on.
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