What is Scada Systems and How Does it Work?

What is SCADA?

SCADA stands for supervisory control and data acquisition, it is a control system architecture that consists of networked data communications, graphical user interfaces, and computers for high-level process supervisory management.

It also consists of various other peripheral devices like discrete proportional integral derivative and programmable logic controllers which are known for interfacing with process machinery and plant. SCADA systems are used for operating and managing project-driven processes in construction.

The SCADA computer system is known for handling various operator interfaces which are known for enabling the issuing and monitoring of process commands like controller setpoint changes.

The real-time control logic or controller calculations which are an example of subordinated operations are performed by the networked modules which are connected to the field actuators and sensors.

The concept of SCADA has become a universal means of remote access to various local control modules as it was developed in this way. The manufacturers of SCADA are different and are known for allowing access via standard automation protocol.

When in practice, the huge SCADA systems have grown up to convert into the same kind of distributed control systems that are in function. These are known to control for controlling the large-scale processes which comprise numerous sites. These are capable of working over large distances as well as small distances.

SCADA System Components

A SCADA system comprises various essential elements such as supervisory computers, programmable logic controllers, remote terminal units, human-machine interface, and communication infrastructure. Let’s read about these SCADA system components in detail.

Supervisory Computers:

Supervisory computers form the core of SCADA systems and are known for gathering data on the process. These are known for transferring the control commands to the field-connected devices. These refer to the software and computer that are responsible for communicating with the controllers that connect the field.

Programmable Logic Controllers:

Programmable logic controllers, commonly known as PLCs are connected to actuators and sensors in the process. These are known for being networked to the supervisory system. When it comes to factory automation, these have a connection of high speed to the SCADA systems

In remote applications like a large water treatment plant, these can connect directly to SCADA via a wireless link. These are specially designed for controlling and acted as a founding platform for programming languages.

Remote Terminal Units:

RTU or remote terminal units connected to the actuators and sensors in the process. These are connected to the supervisory computer system through a network. These have control capabilities that are embedded and mostly conform to the programming standard and support automation.

Human-Machine Interface:

HMI or human-machine interface acts as an operator window of the supervisory system. It is known for presenting the information of plants to the operating personnel in a graphical manner. These graphical diagrams comprise mimic diagrams which are the schematic representation of the plant which is being controlled, event logging pages, and alarm.

The human-machine interface is linked to the SCADA supervisory computer to drive mimic diagrams, trending graphs, and alarm displays by providing live data. The HMI acts as a graphical user interface for the operators in numerous installations. It collects the data from external devices, sends notifications, performs alarms, and creates reports.

Communication Infrastructure:

The communication infrastructure is known for connecting the supervisory computer system to the PLCs and RTUs. They may utilize manufacturer proprietary protocols or industry standards but both PLCs and RTUs are known for their autonomous functioning on the near-real-time process control. 

Types of SCADA

The SCADA systems are of four types are Monolithic SCADA system, Distributed SCADA system, Networked SCADA system, and IoT SCADA system. Let’s read about these types of SCADA in detail.

Monolithic SCADA System:

These systems are the first-generation systems that make use of minicomputers. These systems may be developed in the absence of commonly used network services. These systems may be designed as independent systems without any specific relation to the other.

Distributed SCADA System:

Distributed SCADA systems are the second-generation systems; the control functions may be distributed across various systems by joining them with LAN or local area network. By sharing command processing and real-time data, the control operations may be performed.

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The cost and size of each station get reduced in these types of systems. However, it is to be noted that they don’t have any consistent protocols as such. Very few people understood the SCADA system security as the protocols were considered proprietary.

Networked SCADA System:

These systems are known as the third-generation systems; the communication and network of the present SCADA systems may be done by utilizing the WAN system via phones or data lines. The transmission of two nodes may be done by taking the help of Fiber-optic connections or Ethernet.

IoT SCADA System:

IoT SCADA systems are the fourth-generation systems that have reduced cost as a result of IoT implementation via cloud computing. The maintenance of these systems is considered easy in comparison to the others.

In real-time, the condition of these systems may be reported via cloud computing. This is why the implementation of the algorithms comprising of intricate control may be performed that are generally used on usual PLCs.

Examples of SCADA Use

SCADA systems are used in various industries, especially in places where it is tough to have a human presence due to a lack of security. This may be a result of various factors that contribute to it. This comprises a facility in a remote area that is tough to reach on time.

Let’s read about the examples of SCADA use. A general SCADA network may be set up for monitoring leakages in a pipeline. Once the leak is detected, the system carries on pre-configured commands.

The devices which carry on these functions are either remote terminal unit (RTU) or programmable logic controller (PLC). The remote terminal unit is generally considered as the device of choice as it brings with it more control and automation features for the management system.

Applications of SCADA System 

The application of the SCADA system is done in different industries in various forms. Let’s read about the industries in detail.

Electric power generation, transmission, and distribution: The electric utilities make use of RTI, PLC, and HMI SCADA for detecting the flow of current and voltage lines of remote sites. These are used for monitoring the operation of breakers and for taking power grids on and off. SCADA systems may be found at the electrical power distribution from coal, nuclear, electrical power distribution and transmission, gas-fired coal, etc.

Water, wastewater, and sewage: The municipal water and state utilize SCADA applications. These are known for monitoring and regulating reservoir levels, water flow, wastewater collection and treatment facilities, pipe pressure, water treatment distribution, and centers and different factors of the field devices.

Buildings, facilities, and environments: The facility managers are known for using SCADA for monitoring and controlling HVAC, refrigeration units, lighting, temperature sensors, and entry systems.

Manufacturing: The other application of SCADA includes managing part list for manufacturing just-in-time and regulating industrial robots and automation. It is used for monitoring the quality and controlling the process in industrial plants.

Mass Transit:

The SCADA protocols are used by the transit authorities for regulating the electricity in remote areas. It is also used for automating traffic signals for tracking and locating buses and trains and for controlling the railroad crossing gates.

Traffic Signals:

SCADA is used for controlling traffic flow, regulating traffic lights, and detecting out-of-order signals.

Oil and Gas:

SCADA software application is used for remotely monitoring and controlling the equipment which is related to pumps, storage, pipelines, onshore wells, offshore platforms, refineries, and petro-chemical stations.

Food and Beverage Production:

It is very important to keep the temperature within an adequate range while making and processing food. These systems are used for monitoring and controlling temperatures within these facilities.

How to Secure SCADA Systems

SCADA or supervisory control and data acquisition network is widely used in various modern industrial organizations for monitoring and analyzing real-time data, interacting with devices, and controlling local as well as remote industrial processes. Let’s read more about how to secure SCADA systems. 

SCADA systems play a very important role in the industrial organizations which use them. The reason is that these are comprised of software and hardware which may or may not be subject to vulnerabilities. This system is a growing requirement in the industrial sector.

SCADA security is a broad term that may be used for describing the procedure of protecting SCADA networks. These networks are created from computer hardware and application for their requirement in controlling and monitoring the vital infrastructure in places where these are put to use.

Some of the systems which use SCADA networks comprise electricity, natural gas, water, and some other key services. As a result of its role and vulnerabilities of networks, some measures are taken by the government as well as private companies for ensuring the safety of these systems.

SCADA security is a term that has been used for describing the measures which have been taken for protecting the SCADA networks and for discussing the vulnerabilities. The major threats have been specifically divided into four categories, these include malware, hackers, inside errors, and terrorists.

These networks are made up of firmware, software, and hardware. The newer networks are at least partially in control of the applications. It has been noted that each point of the network has unique security threats. However, the hackers are said to be targeting systems which have similar kind of weaknesses.

Although there are numerous points of vulnerability and multiple effective measures for protecting it, there are a few components of it that are common to any network. These preventive measures may be employed by any of the industrial control networks.

One of the best practices of SCADA security includes mapping all the current systems. The system which is connected to the internal network and internet must be documented. Every piece of software, firmware, hardware, and application requires to be a part of the map in the entire SCADA network.

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Numerous SCADA systems are presently used for monitoring and as detection systems. This makes them highly vulnerable to malware and attacks. Network segmentation may be employed for separating the other crucial business systems. It is vital to align physical security along with cybersecurity measures.

Security is something that requires continuous attention and therefore, it is necessary that security checks, standard protocols, and report monitoring are instituted. It must be followed by everyone who has access to the SCADA network.

Risk, asset, and vulnerability assessments must be conducted on a continuous basis in order to adapt security measures. This will help in handling the problems immediately without causing any delay which might worsen the situation.

The security policies and effective controls must be carefully thought out so that the present industrial control systems may be adequately secured. To implement an action plan, it is necessary to understand the common weakness first so that the security may be taken to an acceptable level.

Features of SCADA Systems

The features of SCADA systems are numerous such as trend curves patterns, data access and retrieval, computer networking and processing, and alarm handling.

Trend Curves Patterns:

The trend curves and patterns comprise trend zooming and data display. It is known for performing export and archiving historical trend data. It does so with event-based trends for short as well as long-term trend displays. It contains an option of online change in the time-base along with retrieval of archived historical trend data.

Data Access and Retrieval:

The real-time access and the retrieval of data consist of real-time access which occurs directly to the data by any network user along with third-party access to the real-time data. It is said to have network compatibility for reading, writing, and executing the input and output device points.

Computer Networking and Processing:

Computer Networking and Processing is known for supporting compatible protocols and networks. It comprises of trend, report, and alarm processing from data that is available from any place in the network as well as dual networks for complete LAN redundancy.

Alarms Handling:

Alarm handling especially comprises of time-stamped alarms up to 1-millisecond precision. It is a single network acknowledgment and controls alarms by sharing and displaying alarms to its users in a chronological form.

Further, it is known for performing dynamic alarm allocation of pages and keeping track of deviations along with the rate of change monitoring for the analog alarms. It also has an option for event logging and historical alarm.

SCADA systems have multiple benefits which include an increase in the life of the equipment that is used via immediate information received of the performing system. It reduces the labor cost which is required for services or troubleshooting.

There is increased compliance with the regulatory agencies that occurs via the automated report generation. When it comes to these systems, there is no requirement for large capital investment. There are numerous companies that use this system for providing access to the real-time display of data, trending, reporting, alarming from remote equipment.