What is SCADA? Supervisory Control and Data Acquisition – Defining The System


What does SCADA stand for?  

SCADA system or SCADA is short for Supervisory Control and Data Acquisition. The purpose of a SCADA system is to control and monitor specific system architecture that provides automation through software and hardware solutions that collect, analyze, manage, and visualize data at the edge.  

How does the SCADA system Work?  

A SCADA system is a centralized control system that helps optimize industrial processes, especially for larger-scale setups. SCADA utilizes SCADA software that runs within the supervisory computers, managing, controlling, and receiving data from various industrial equipment, sensors, and actuators. These devices are linked to the PLCs and RTUs that manage the SCADA system's communication with the field devices. Another essential part of a SCADA system is the GUI (Graphical User Interface), such as HMIs and Panel PCs.   

A SCADA system uses data visualization displayed on the HMIs for the field workers to monitor the overall system's performance with near real-time data updates. The HMIs can also perform actionable commands when the equipment's processes need some adjustments. All of these integrated SCADA systems are connected by communication infrastructures using LAN or Ethernet that connects to the central SCADA server. The SCADA server can be located in various places from the local factory floor, remote offices, or entirely designed to run in the cloud.  


4 Components of SCADA Systems: 

1. Supervisory Computer 

    A supervisory computer is the core of the SCADA system. In a SCADA system, one or more supervisory computers can gather data and send control commands to the field devices through the communication networks. In addition, the supervisory computer runs SCADA software that enables it to communicate with the field connection controllers such as RTUs, PLCs, and HMIs.   

    2. Remote Terminal Units 

      RTUs or Remote Terminal Units are microcomputers that connect SCADA systems to various sensors and actuators to the supervisory computer system. Most RTUs do not use non-volatile memories to save the data gathered from the field devices. Therefore, RTUs focus on transmitting the data to and from the central SCADA system or the supervisory computer. Despite the limitations, RTUs are cheaper and rugged, capable of surviving harsh industrial environments with wide temperature ranges. An RTU also conforms to the IEC 61131-3 standard to support automation programming using ladder logic, blog diagrams, or other languages.  

      3. Programmable Logic Controllers 

        PLCs or Programmable Logic Controllers are microcomputers that transmit telemetry data to the SCADA system from numerous field devices and to the supervisory computer system. Similar to RTUs, PLCs can also execute control programs received from the SCADA system. PLCs are often compared with RTUs. Compared to RTUs, PLCs are more capable of processing more complex automation and critical controls. With PLCs, SCADA systems can be more versatile with the ability to write more codes and handle more bandwidth. However, PLCs are more expensive than RTUs and require a narrow temperature range for environmental control.   

        4. Human-Machine Interfaces 

          HMIs or Human-Machine Interfaces provide a GUI (Graphical User Interface) of the SCADA system to monitor the information from the supervisory system. The SCADA system's information displayed on the HMIs is typically presented in mimic diagrams, line graphics, process elements, and equipment conditions, which are a schematic representation of the SCADA system controlling the plant. Filed workers can also issue commands using a mouse, keyboard, or touch screens to control and adjust all the hardware integrated within the SCADA system.  


          Main Functions of SCADA System  

          Data Acquisition: gathers and processes real-time data from field devices. Typically converts various analog data into digital information.  

          Data Presentation: data collected from the fields are processed, organized, and presented as a visualization for operators to monitor and control the processes.  

          Control: enable users and operators to remotely or locally perform commands and make adjustments of specific functions that directly interact with the field devices.

          Networked Data Communication: data collected from the field is transmitted in real-time or in response to request commands. The communication channel can be digital (TCP/IP, RS485) or analog (POTS, T202). The SCADA system also records events into a log file or fed data to a historian for future analysis.  


          SCADA Control System Architecture  


          Looking deeper into the SCADA models, there are five levels of manufacturing within the general SCADA control system architecture. In addition, there are diverse supervisory control and data acquisition systems that may have different functional levels depending on their size and complexity. Here are the five levels of SCADA systems:  

          Level 0: This functional level is the tip of SCADA systems comprising field devices, industrial equipment, sensors, and actuators. This part of the functional level is where the SCADA system gathers data in order to provide better control in factory plants using hardware such as flow and temperature sensors, control valves, pumps, conveyor belts, robot arms, and much more.   

          Level 1: This level consists of microcomputers such as PLCs and RTUs that work as the industrialized I/O modules of the SCADA system. The PLCs and RTUs convert the signals collected by the field devices into digital data and sent to the SCADA supervisory system.  

          Level 2: This level is where supervisory computers collect information from processor nodes on the SCADA system in order to provide visualization for dedicated HMIs.  Level 2 is the functional level where data can be fed into a database server for future analytics and auditing.  

          Level 3: This level is known as the production control level of a SCADA system. The production level does not directly control the field devices. Instead, this level focuses more on monitoring the production and targets of the factory. This information can be monitored remotely or at the plant through HMIs.   

          Level 4: This is the production scheduling level, the last level of the SCADA system. This is the level where managers can set production schedules remotely or onsite. Then, based on the information provided by the SCADA system, managers can adjust the production's throughput to meet the desired supply influenced by various factors such as forecasted demands, logistics, and current inventories.   


          Brief History of SCADA Control Systems – SCADA Evolution  

          SCADA has evolved from providing supervision and control to offering real-time telemetry and advanced automation. Here are the milestones of SCADA systems integration that have evolved through four generations:   

          First Generation – Monolithic  

          The concept of SCADA was born from the effort of industrial organizations to solve the problem of relying on human operators to manually monitor and control equipment using pushbuttons, selector switches, and analog dials. As a result, industrial floors and remote sites started to develop SCADA systems to monitor and control processes via large mainframe computers. At this time, SCADA systems were independent systems that used strictly proprietary communication protocols that could not connect to any other systems.   

          Second Generation – Distributed  

          Around the 80s and 90s, LAN or Local Area Networking technology was introduced to the SCADA system. With LAN, SCADA systems are connected across smaller computers with near real-time information updates. With LAN and PC-based HMI software, the command system was distributed across multiple stations where each station was responsible for a specific task. Therefore, distributed SCADA systems are more cost-effective and require fewer filed operators than the previous generation. Unfortunately, the network protocols were still proprietary and incapable of communicating with other systems with different vendors.   

          Third Generation – Networked  

          In the early 2000s, SCADA implemented open system architectures with a standardized communications protocol that was not vendor-specific. As a result, SCADA systems could be scaled down to simpler components and protocols that were popular for interoperability and streamlining connections – ethernet. The ability for connectivity through a network provided access to SCADA systems from different locations across the globe. With a process control network (PCN) that consists of various LAN networks, large-scale SCADA systems are much more cost-effective in comparison to traditional setups.  

          Fourth Generation – Web-Based  

          The current web-based SCADA system has adapted to current technologies with the adoption of modern IT, such as personal computing, structured query language (SQL) databases, and web-based applications. Web-based SCADA allows users and operators to view and control data from anywhere through the internet in real-time or in the cloud. The plant information can be accessed through internet browsers such as Google Chrome that exhibit a specific HMI software's graphical user interface (GUI). That being said, the web-based SCADA system has the most scalability and flexibility for industrial organizations.   


          Applications with SCADA System Integration:  

          SCADA systems are widely integrated to automate various industrial applications. SCADA has truly become the backbone for industrial automation setups that provide industrial processes' safety, efficiency, and reliability, especially for mission-critical applications. Here are the applications with SCADA system integration:  

          • Energy and Power Grids  
          • Remote Oil and Gas Facilities  
          • Transportation Systems  
          • Water Management and Wastewater Treatment  
          • Manufacturing Sites  
          • Food and Beverage  
          • Wind and Solar Farms  
          • Telecommunications  
          • Agricultures  
          • And many others  


          Modern SCADA – IoT SCADA System  

          Modern SCADA systems are implementing the latest technologies such as cloud computing, high-speed wireless connectivity, IIoT (Industrial Internet of Things), and AIoT (Artificial Intelligence of Things). Modern SCADA software is developing rapidly and requires modern hardware technologies to streamline the processes in an efficient and easy manner. The IoT SCADA system reduces infrastructural costs by controlling IoT devices through cloud management dashboards. Therefore, many of the latest SCADA architectures are increasingly replacing hardwired SCADA system infrastructure with the benefits of wireless communication technologies.   

          Moreover, industrial automation implements intelligent AI models such as machine vision within the factory floor to increase autonomy. There is a myriad of computing devices that can be upgraded to implement modern SCADA architectures. However, there are two industrial solutions that can provide a more streamlined, intelligent, and reliable SCADA system. These are Industrial Panel PC and Rugged Machine Vision Computers. That being said, Premio offers robust Industrial Panel PCs and Rugged Machine Vision Computers to replace traditional PLCs, RTUs, and Supervisory Computers.   


          Industrial Panel PC for SCADA – VIO Series  


          VIO series panel PCs are the right solution for modern SCADA systems designed specifically for HMI automation, information, and communication applications. The innovative modular design makes the display system more flexible and versatile by providing a modular design with interchangeable Panel PC or Touch Monitor modules. Moreover, the VIO series can easily withstand a wide range of extreme environmental challenges, great for harsh SCADA deployments in automation setups.   

          Key Features:  

          • Patented modular design with the Multi-Mode Display Module  
          • Rich I/O options for SCADA field devices  
          • IP65 industrial display panel  
          • Intel 7th Gen (Kaby Lake-U) Processor Core i5-7300U  
          • -10°C to 60°C extended operating temperature  
          • Rich I/O for SCADA field devices controls (DIO, USB 3.0, RS-232 COM, RJ45 LAN)  

          Learn More About Modular Industrial Panel PCs  

          Machine Vision Rugged Computer for SCADA – VCO-6000-CFL Series  


          VCO machine vision rugged computer is an all-in-one industrial edge solution for your intelligent SCADA systems. The VCO series covers the functions of PLCs, RTUs, and Supervisory Computers with additional Machine Vision capability when connected to cameras. Additionally, the VCO series are built, tested, and validated to withstand extreme industrial deployments. As a result, the machine vision computer series is primed for modern SCADA applications such as automatic product line inspection, intelligent security surveillance, biomedical imaging, and vision-guided robotics/vehicles.   

          Key Features:  

          • 9th Gen Intel® CFL-R S Processor  
          • Wide Operating Temperature (-25°C to 70°C)  
          • Rich I/O for SCADA field devices controls (DIO, USB 3.2 Gen2, RJ45 LAN, RS-232 COM)  
          • Full-Length x16 PCIe GPU Accelerator  
          • Hot-Swappable Fan  
          • NVMe SSDs Storage Expansions  
          • Up to 3x PCIe and 2x PCI Expansions  

          Learn More About Rugged Machine Vision Computers  

          Premio is a global solutions provider that has been designing and manufacturing top-notch industrial computers for over 30 years in the United States. Our solutions are designed to operate reliably and optimally in the most challenging environmental conditions. Moreover, Premio's Industrial Panel PCs and Machine Vision Rugged Computers are specifically built to withstand extreme environments amid remote industrial SCADA deployments. In conclusion, Premio offers the most high-end and customizable computing solutions for industrial automation systems such as SCADA. If you need assistance finding the best SCADA computing solutions, don't hesitate to contact us. One of our industrial computing professionals will assist your best industrial computing solution based on your specific needs.