SCADA Introduction :
- SCADA stands for supervisory control and data acquisition.
- It is a type of software application program for process control.
- SCADA is a central control system which consist of controllers network interfaces, input/output ,communication equipment’s and software.
- SCADA systems are used to monitor and control the equipment’s in the industrial process which include manufacturing, production, development and fabrication
- The SCADA system takes the reading of the meters and checks the status of sensors in regular interval so that it requires minimal interference of human.
What Is SCADA:
SCADA stand for Supervisory Control and Data Acquisition. SCADA generally refers to an industrial computer system that monitors and controls a process. In the case of the transmission and distribution elements of electrical utilities, SCADA will monitor substations, transformers and other electrical assets.
SCADA refers to a system that collects data from various sensors at a factory, plant or in other remote locations and then sends this data to a central computer which then manages and controls the data.
A SCADA system allows an operator in a location central to a widely distributed process, such as an oil or gas field, pipeline system, irrigation system or hydroelectric generating complex, to make set point changes on distant process controllers, to open or close valves or switches, to monitor alarms, and to gather measurement information. When the dimensions of the process become very large-hundreds or even thousands of kilometers from one end to the others-one can appreciate the benefits SCADA offers in terms of reducing the cost of routine visits to monitor.
Advantage of SCADA:
- The SCADA system provides onboard mechanical and graphical information.
- The SCADA system is easily expandable. We can add set of control units and sensors according to the requirement.
- The SCADA system ability to operate critical situations.
- The system provide facility to store large amount of data.
- The data can be displayed in various formats as per user requirements.
- It provides interface to connect thousands of sensors across wide region for various monitoring and controlling operations.
- It is possible to obtain real data simulations with the help of operators.
- Many types of data can be gathered from RTUs (Remote Terminal Units) connected with the master unit.
- It is fast in obtaining response.
- It is scalable and flexible in adding additional resources.
Disadvantage of SCADA:
- PLC based SCADA system is complex in terms of hardware units and dependent modules.
- As the system is complex, it requires skilled operators, analysts and programmers to maintain SCADA system.
- Installation costs are higher.
- The system increases unemployment rates.
- The system supports use of restricted software and hardware equipment.
Components of SCADA:
Human-Machine Interface : is the apparatus which presents process data to a human operator, and through this, the human operator monitors and controls the process.
Remote Terminal Units : connecting to sensors in the process, converting sensor signals to digital data and sending digital data to the supervisory system.
Programmable Logic Controller : The plc is automate industrial automation process and they easily interface with scada for control the process .
Communication infrastructure : Connecting the supervisory system to the Remote Terminal Units. Communication transfer data between field devices and central server this process can be done wired, wireless and cloud base solution.
Central Servers : This is where all the data stored, processed, and visualized. central server enabling real time decision making.
Feature of SCADA:
- Intelligent Alarming
- Web Connectivity
- REAL TIME AND HISTORICAL TREND
- RECIPE MANAGEMENT
- SECURITY
- DEVICE CONNECTIVITY
Application of SCADA:
Groups of small hydroelectric generating stations: that are turret on and off in response to customer demand are usually located in remote locations, they can be controlled by opening and closing valves to the turbine, they must be monitored continuously, and they need to respond relatively quickly to demands on the electric power grid.
Oil or gas production facilities: including wells, gathering systems, fluid measurement equipment, and pumps are usually spread over large areas, require relatively simple controls such as turning motors on and off, need to gather meter information regularly, and must respond quickly to conditions in the rest of the field.
Pipelines: for gas, oil, chemicals, or water have elements that are located at varying distances from a central control point, can be controlled by opening and closing valves or starting and stopping pumps, and must be capable of responding quickly to market conditions and to leaks of dangerous or environmentally sensitive materials.
Electric transmission: systems may cover thousands of square kilometers, can be controlled by opening and closing switches, and must respond almost immediately to load changes on the lines. E. Irrigation systems often cover hundreds of square miles, can be controlled by opening and closing simple valves, and require the gathering of meter values for the water supplied to consumers.
The leading SCADA manufacturers:
- Siemens
- Schneider Electric
- ABB
- Honeywell
- GE Digital
- Rockwell Automation
- Emerson
- Yokogawa
- Inductive Automation
- Iconics
- AVEVA (formerly Wonderware)