What Is SCADA and How Does It Work?

SCADA (Supervisory Control and Data Acquisition) is a computer-based system used for controlling and monitoring machines and processes based on real-time data. 

It is a collection of software and hardware components used for industrial automation which enables managers, engineers, and other industry workers to communicate effectively with the working environment. 

What Are the Key Components of a SCADA System?

The main components of SCADA are: 

• Sensors and actuators – Sensors are tools that gather data based on physical characteristics like temperature or pressure and transmit it to the SCADA system. Actuators, on the other hand, are machines that use the data to take a certain action. They represent the fundamental components of a SCADA system.
• Supervisory computers – Collect data from the sensors, analyze it, make decisions based on it, and send commands to the actuators. They connect to, communicate with, and control all the remote terminals and devices.
• SCADA field controllers – Are the devices located near the field where the process is being controlled. They are connected to the sensors and actuators where they collect data from sensors, send it to the supervisory computer, and receive commands from the supervisory computer which are afterward sent to the actuators.
  They are designed to operate in harsh environments and have a wide range of inputs and outputs. Two types of SCADA field controllers are:
  • Programmable Logic Controllers (PLCs) – These are specialized industrial computers that are used to control industrial processes by receiving input data from sensors, processing the data, and sending commands to actuators. 
  • Remote Telemetry Units (RTUs) – These are specialized devices used to collect data from remote locations and process the data, after which the data is sent to the supervisory computer using a communication protocol, such as Ethernet, serial, or wireless. RTUs are typically located in the field, near the process being controlled, and are connected to sensors and actuators. 
• Human-Machine Interface (HMI) - A software application or hardware device that allows operators and engineers to interact with the SCADA system by displaying information in a graphical format. By transforming the data, HMI allows humans to understand and monitor the process and control it by sending commands to the actuators.
• Communication infrastructure - Represents the network of devices and communication protocols used to transmit data between components of SCADA systems. This includes the communication between the supervisory computers, the field controllers, sensors, and actuators. 

How Do SCADA Systems Work?

SCADA systems obtain and collect data from sensors and network devices attached to PLCs or RTUs before converting it into a central control room where it can be analyzed and displayed on HMI into information that humans can understand. The control room operator can then use this information to make decisions and control the remote equipment.

SCADA systems are designed to be flexible and can be configured to control a wide variety of industrial processes, monitoring and controlling various parameters like temperature, flow, pressure, humidity, voltage, and current. 

What Are the Four Types of SCADA? 

There are many different types of SCADA systems, however, they can be broadly categorized into four categories:

• Monolithic SCADA system (first generation) – This type of SCADA system performs all of the system's functions, including data collection, processing, display, and control. To do so, monolithic SCADA system uses a single and centralized software program.
• Distributed SCADA system (second generation) – This kind of system uses a distributed control and data collection architecture. It enables a decentralized control and monitoring of tasks. This allows for greater flexibility, scalability, and the ability to handle larger amounts of data.
• Networked SCADA system (third generation) – These systems are characterized by the use of modern communication technologies and the integration of various IT and control systems. It is designed to be more flexible, secure, and efficient than the first and the second generation. Networked SCADA systems have advanced security features, such as encryption, firewalls, and intrusion detection to protect against cyber threats.
• Internet of Things (IoT) SCADA system (fourth generation) – Is characterized by the integration of IoT technologies, the use of cloud computing, and big data analytics. These systems are designed to be even more flexible, efficient, and scalable than the other SCADA systems. In this system, control and monitoring functions are performed by a network of many intelligent devices. 

Benefits of SCADA Systems

SCADA is used in many industries like electricity, oil and gas, telecommunication, transportation, etc., where it assists them in automating and managing many processes. SCADA systems provide many benefits, such as:

• Scalability
• Real-time monitoring and controlling
• Automation
• Remote access
• Reduce costs and energy
• Safety
• Efficiency
• Reduce downtime

SCADA Security 

SCADA systems are vulnerable to security threats such as cyber-attacks, which can have significant consequences, for instance, loss of control over industrial processes, disruption of services, and even physical damage to equipment.

SCADA security can be a critical aspect which is why it requires an integrated protective approach. To help it mitigate the risks and protect it from potential threats, it is important to implement a comprehensive security program that includes the following elements:

• Network segmentation – Is dividing the SCADA network into smaller segments to limit the scope of a security incident and make it more difficult for an attacker to move laterally through the network.
• Access control – This involves implementing strict access controls to limit who can access SCADA systems and what actions they can perform. This can involve measures such as user authentication, role-based access controls, and least privilege principles.
• Security monitoring – This means implementing security monitoring and incident response capabilities to detect and respond to security incidents. This can include measures such as intrusion detection systems, security information and event management (SIEM) systems, and incident response plans.
• Patch management – This entails keeping SCADA systems and associated software up to date with the latest security patches and updates. This can help to prevent known vulnerabilities from being exploited by attackers.
• Security awareness training – Providing training to employees and other stakeholders on how to identify and mitigate security threats.
• Penetration testing – Regularly performing penetration testing to identify and remediate vulnerabilities in the SCADA systems.

SCADA Security Manager Training Course 

PECB’s SCADA security manager training course is designed to provide individuals with the knowledge and skills needed to effectively manage the security of SCADA systems. The course covers various topics related to SCADA security, including its fundamental principles and concepts, SCADA environments and systems risk management, methodology for the implementation of a SCADA Security program, etc. 

About the Author

Vlerë Hyseni is the Digital Content Officer at PECB. She is in charge of doing research, creating, and developing digital content for a variety of industries. If you have any questions, please do not hesitate to contact her at: content@pecb.com