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What is SCADA and Why Use It?

By Telstar Inc |

SCADA is part of the Industry 4.0 wave — but is it just hype, or does it have a place in your business?

That’s a question worth asking and answering, especially if you want to stay competitive these days. You have options, and you need to know what they are.

SCADA applications empower businesses through remote monitoring. It’s often used to control critical functions and gather and incoming data that help keep your operations running smoothly.

At least, that’s the high-level picture. We want to get into the gritty details and show you why it matters.

In companies across North America, SCADA is already a linchpin for smarter and more cost-effective control of power systems. Here’s everything you need to know to ensure it’s right for you.

What Is SCADA?

SCADA is the acronym for Supervisory Control and Data Acquisition. SCADA denotes an automation control system favored in large-scale industrial, manufacturing, construction, and engineering industries like oil and gas, water, power, pharmaceuticals, and more.

But SCADA can be hard to pinpoint because it’s not a specific technology — it’s a process. Think of it as a type of application that receives operating data about a series of systems. The application then uses the incoming data to control and optimize the running of the system in a proactive, even predictive way.

You begin with a centralized system that monitors and controls sites, from a single plant to a complex series of factories spread across the country.

SCADA works by operating with incoming signals from switches and devices. A remote user can read the incoming data and then control equipment without needing to be present.

The application also relies on a distributed database of tags or points through the plant. These points are information about a single input or output value, telling the SCADA system what’s going on with monitored and controlled equipment.

SCADA also acquires and stores metadata, such as programmable logic controllers (PLCs), register paths, and alarm statistics. Together, this architecture enables:

  • The control of industrial processes locally, or at remote locations.
  • The monitoring, gathering, and processing of real-time data.
  • Direct interaction with devices like sensors, valves, pumps, and motors through HMI software.
  • The recording of events into a log file.

When you look at the SCADA model in graphical form, it’s easy to see that it’s a feedback loop with a parallel branch of analytics. Using temperature sensors and RTUs, for example, a SCADA server receives information about the information, for further analysis and decision-making.

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Common SCADA system components include:

  • Remote Terminal Unit (RTU): A field device, like PLCs, that uses industrial data communication protocols to transmit the sensor/on-site device data. RTUs are more potent than PLCs because they are intelligent controllers used to assert control over other devices and then automate industrial processes.
  • Radio/Modems: Through wireless transfer, radios and modems send and receive real-time data in an efficient and reliable way.
  • Sensor/Transducers: Sensors receive a signal from a physical system, then communicate through the use of telemetry and control systems. These sensors help technicians/operators of the SCADA system to measure and collect data remotely.
  • Repeaters: Like a satellite, repeaters receive and then re-transmit signals over vast distances, even in the presence of physical obstruction.
  • SCADA Master Station: The master station is the dashboard, the central control station for all other operations. It may be a single computer, or it may be multiple servers, software applications, RTUs, and PLCs for more complex operations.
  • Monitoring software: The monitoring software is responsible for instructing the system and setting up a baseline of data instructions. These instructions direct the system on how to interact with all hardware, the expected values, and what performance metrics are desirable
  • Human Machine Interface (HMI): Once the SCADA host scans the data, HMI software detects alarm conditions, which then tells the operator something needs attention

SCADA is not just a matter of convenience. It can also be a matter of safety.

Industries like oil and gas, electrical and water utility stations, water and wastewater treatment facilities, and environmental monitoring sites rely on SCADA communications and data gathering because the resources are so remote.

Even if they can be accessed, it’s sometimes safer for plant operators to stay clear — especially if a remote monitoring system can do the job of measuring and collecting at regular intervals.

Oil wells, water wells, and generator stations are just a few examples of assets that rely on the SCADA architecture, which relies on the age-old operation of telemetry.

Telemetry Monitoring

The SCADA application would be nothing without telemetry monitoring.

Telemetry is a crucial part of acquiring, receiving, monitoring, and analyzing incoming data about the conditions of equipment in real-time.

Meteorological systems that measure, monitor, and predict the weather are a good example of a telemetry monitoring system. Telemetry monitoring is done remotely and calls for a set of data collecting instruments hooked up (even wirelessly) to a set of IT systems.

The communication between the two interfaces is through technologies like radio, ultrasonic, infrared, telephone, or computer networks.

Telemetry units used in SCADA come in four types:

  • Wired: Located physically in a plant and includes Ethernet, dial-up phone lines, and leased lines to remote sites .
  • Wireless: Includes in-plant wireless networks like Wi-Fi, cellular networks, satellite networks, and point-to-point radio networks with repeaters.
  • Polled: Reporting here is based on exceptions.
  • Hybrid: A combination of one or more of the previous units.

With the advent of big data, telemetry is increasingly useful. It provides a data-rich transit system which can power up sophisticated and detailed intelligence through aggregation in centralized systems.

Modern Day SCADA Systems

Modern-day SCADA systems are increasingly relying upon cloud-based SCADA applications to re-imagine the SCADA architecture.

The concepts in the model are the same, but the physical equipment is often digitized and automated, making operations more intuitive, flexible, and scalable.

Today, modern SCADA systems bring the best of control devices to the flexibility and functionality of IT technology. Modern SCADA systems are all about operating in real-time: access, transparency, control, and decision-making.

Seven Golden Rules of SCADA Success

SCADA’s true efficacy is its role in the organization’s broader goals.

SCADA occupies a very strategic position at the center of the automation pyramid:

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With operations, SCADA controls and monitors incoming data and operations, as expected.

It also responds and sends crucial information to MES and ERP software. Successful SCADA implementation allows you to translate operational data into actionable business intelligence and planning.

1) Systems Matter

Your choice of systems should be aligned with your sector’s and industry’s requirements, while also choosing a provider with a reputation for scalable solutions.

2) Get Network Integration Right

Is downtime an inevitability when migrating from one system to another? Significant downtime can mean data loss, damaged data integrity, or possible inaccurate data transfer. Plan for these contingencies because any losses could be catastrophic.

3) Prepare For Environmental Hazard

RTUs make it safer for human operators to access relevant information. But even RTUs can experience damage when exposed to the elements. Choose equipment that aligns with your region’s climate and schedule in periodic (or even predictive) maintenance.

4) Plan For Replacement Of Obsolete Units

Planned obsolescence of units means you can plan for replacement. In the meantime, be sure to choose SCADA components designed to provide for future expansion and maximize equipment flexibility.

5) Keep Security Threats At Bay

The running of the software is just as important as its implementation.

68% of IT professionals say that denial of service attacks, known as a DDOS, is the most common method of interrupting and exploiting SCADA systems.


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As powerful as SCADA is, it’s still vulnerable to attacks.

Part of that vulnerability comes from the way Industrial Internet of Things (IIOT) is changing the instrumentation and controls landscape.

Cybersecurity for SCADA needs to be as proactive and predictive as its monitoring and maintenance of equipment.

6) Assess Vulnerabilities Regularly

Think about threat- and vulnerability assessment like performing routine and preventative maintenance on equipment. It’s not enough to simply report attacks — to protect your SCADA systems network, you’ll need to have a specific plan for prevention.

Even closed systems with no external communication interfaces are at risk.

It’s crucial, unavoidable, and necessary. Run all possible scenarios and types of attacks, using either in-house or external specialists, with experienced technicians who know how to respond to external attacks.

7) Strike A Balance

SCADA’s strategic position between operational technology and high-level planning initiatives make it a powerful tool for business intelligence.

But that’s only if you strike a balance between security and integration. Make sure that there is interoperability of different systems on wide-ranging networks, while still ensuring that it’s not open enough to risk infiltration from rogue devices.


Telstar Instruments knows that SCADA software is mission-critical. As a certified instrumentation and controls integrator, we’ve seen how SCADA is poised to evolve its role to the next level as a valuable intelligence hub.

Rather than IIOT driving SCADA systems out, we’re seeing how priorities like flexibility and data-driven decision-making are re-imagining the function of modern-day SCADA systems.

Since integration is the order of the day, SCADA systems are not going anywhere.

Instead, we’re going to see how IIOT hallmarks like cloud computing, mobility and analytics, AI, machine learning, and more, are becoming indicators for successful HIM/SCADA software selection and deployment.