SCADA Systems Explained

What is a SCADA system?

SCADA or Supervisory Control and Data Acquisition is a computer control system that is used to monitor and control plant processes. SCADA uses data communications, graphical user interface, and extended management to monitor systems.

scada system

Note: An overview of SCADA


The biggest manufacturing companies in the world are also known to be the most data-driven establishments. In an age of growing technological capabilities, the importance of collecting data is pushed to the limit with the use of systems such as SCADA.

By collecting and monitoring real-time data, SCADA shows an overview of how each key equipment in the plant is performing. Sensors on the equipment send signals through remote terminal units (RTU) and programmable logic controllers (PLC). This gives the SCADA system the ability to pinpoint anomalies in system functions based on the collected data, thereby allowing the user to promptly take action on the issue.

SCADA allows maintenance personnel to perform more informed decisions. The system is applicable to a wide variety of industries—oil and gas, energy, manufacturing, and virtually any corporation that benefits from accurate and timely data monitoring.

Basic components of SCADA

Think of SCADA as a bridge that links equipment with operators and maintenance personnel. The SCADA system requires some key components to facilitate the transmission of data from the physical equipment to the operator’s display screen.

Note: Components of a SCADA system


The measuring components, which can either be in digital or analogue form, are the sensors. These collect data from various parts of the plant. The complexity of sensors can range from simple binary options such as an on/off signal to more complex sensors that measure flow rate, temperature, and pressure.

Conversion units

Data collected by sensors is only useful if it can be converted into a form that is easily comprehensible. Remote terminal units (RTU) and programmable logic controllers (PLC) are such devices that can translate the data collected by sensors into useable information.

Supervisory system

Various data feeds converted by the RTUs and PLCs converge to a master unit which can be identified as the supervisory system. This system is also commonly known as a human machine interface (HMI), as it is the interface through which the information is made usable to the maintenance personnel.

Communication network

The previously mentioned components are remotely located throughout the plant. These need to be linked together by some communication network. These networks are conventionally wired through telephone lines and circuits. Wireless options have also become available in the form of radio or cellular satellites.

The evolution of SCADA

It is important to note that SCADA systems started out to be standalone systems that eventually evolved to be linked and connected to form a network of devices. Historically, the challenge with SCADA systems was finding an efficient communication network to connect the devices. Earlier technologies relied on proprietary systems to link the components. Though effective to some extent, it had limitations in keeping up with the times.

Meanwhile, up to the early 2000s, IT technologies have been emerging. A particular area in IT systems that showed promising development was in data management in the form of structured query language (SQL) databases.

Modern SCADA systems are starting to incorporate SQL capabilities, further linking to ERP systems for a more holistic and smooth-running operation.

Market research analysts also state that the industrial control systems market—which includes SCADA systems—is projected to reach $181.6 billion by 2024.

Note: 2024 projections of SCADA and Industrial Control Systems


SCADA systems, together with developments in IT technologies, are becoming an integral part of plant systems. SCADA systems enable maintenance personnel to make data-driven choices quickly and efficiently.