Sunday, August 23, 2015

Learn about the 5 components of an SCADA system

Keeping control and supervise on all industrial activities manually can be described as an extremely impossible task. That is exactly where the importance of an automated tool known as SCADA (Supervisory Control and Data Acquisition) system comes in and it performs different activities like controlling, supervising, collecting data, analyzing data and generating reports with utmost efficiency and accuracy. The supervisory control and data acquisition system comprises of different components and they include:

SCADA system

1. Human Machine Interface (HMI)

HMI, an integral component of Supervisory Control and Data Acquisition System connects the machine data with the operator. The Human Machine Interface presents the values stored in the host computers to the human operator in an uncomplicated and comprehensible form. Through this component, the human operator monitors and controls the process.

2. Supervisory (Master Station) Control System

The supervisory or Master Station Control System can be described as the repository of the real-time reported data gathered from the terminal units. The back-end SCADA software polls the remote terminal units for data values and it retrieves stores and processes the data in the best possible manner. The processing includes activities like cataloging into tables and unit conversion as well.

3. Remote Terminal Units (RTU)

A remote terminal unit is a sensor or a transducer that allows the electrical circuitry to connect with the equipment that performs the process instrumentation and control. A change in the electrical property of a certain component in the transducer indicates physical changes and all the physical parameters like temperature and pressure are measured through this change. Different types of physical parameters are measured by a single RTU and the input/output circuitry of an RTU can be digital or analogue as well. Analogue measurements are later converted using an ADC (Analogue-to-Digital Converter) and the most advanced remote terminal units are microprocessor-based devices. It can be said without an iota of doubt that the use of microprocessors has made RTUs highly functional and smarter.

4. Programmable Logic controllers (PLC)

Programmable Logic Controllers have been created around the philosophy of automation. The most important asset of PLCs is reprogramm ability and they can be debugged and fixed on the field itself. Adding different features like exception reporting, time-tagging and support for multiple polling has become extremely hassle free with the most advanced versions. Another important aspect is that PLCs have the ability to execute simple logical processes without directly involving the master station.

5. Communication infrastructure

The communication system conveys data from RTUs to the maser station and it also coveys the commands from the host to the RTU. Since many supervisory control and data acquisition systems are not confined to a single plant alone, network vastness has become a very important issue and other important aspects that should be given proper attention include security, speed, accuracy, and performance as well. Advanced communication systems perform all these tasks with utmost efficiency. Earlier, most communication systems were voice communication-based and they had a lot of limitations like reduced bandwidth and many more. Today, many companies have started including supervisory control and data acquisition information network into their core networks and SCADA systems have also embraced WANs and LANS to ensure seamless integration with everyday office computer networks. It eliminates the possibility of creating a parallel network for these types of systems.


The overall efficiency of modern SCADA systems helps people access real-time data from the plant floor by sitting anywhere in the world and it has made the data-driven decisions on how to improve the performance extremely hassle free for governments, businesses and individuals as well.


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