# SCADA Source: https://ordergroup.co/glossary/scada/ Last updated: 2026-10-10 > SCADA explained for software buyers: how supervisory control works, how it differs from an EMS, the protocols and security rules, and what to require. [Energy](https://ordergroup.co/glossary/energy/) 4 min read # SCADA Supervisory control and data acquisition Also known as: supervisory control and data acquisition, SCADA system Definition Supervisory control and data acquisition (SCADA) is a class of industrial control systems that collects real-time data from field devices and sensors, presents it to operators and sends control commands to equipment across a plant or network. Cite this entry Text "SCADA". Order Group, Software glossary, 10 October 2026. https://ordergroup.co/glossary/scada/ HTML `SCADA - Order Group` Reviewed by [Michał Dżaman](https://ordergroup.co/authors/michal-dzaman/), Co-founder & Head of Backend Last reviewed 10 October 2026 ## How SCADA works SCADA is the layer through which people watch and steer an industrial process: a power plant, a solar farm, a battery site, a substation network or a factory. As the name says, SCADA supervises. Fast closed-loop control runs in local controllers next to the equipment. SCADA collects what they measure, shows it to operators, raises alarms and passes on commands such as start, stop, open or a new setpoint. A typical SCADA system has these parts: - Field devices. Sensors, meters, inverters, protection relays and actuators. - Local controllers. Programmable logic controllers (PLC) and remote terminal units (RTU) that read the field devices and run local control loops. - Communication. Industrial protocols carry data between controllers and the SCADA servers: [Modbus](https://ordergroup.co/glossary/modbus/) at device level, IEC 60870-5-104, DNP3 and IEC 61850 in grid and substation work, OPC UA between systems. - SCADA servers. They poll or receive data, keep the current state of every signal (tag), evaluate alarms and route commands. - Historian. A time-series database that keeps measurements for reports, analysis and investigations. - Human-machine interface (HMI). The screens operators use: plant schematics, trends, alarm lists and command dialogs. Older SCADA systems ran on closed networks with desktop clients. Newer ones often add a web interface and send data to a cloud platform for analytics, a [digital twin](https://ordergroup.co/glossary/digital-twin/) or fleet monitoring, while control stays on site. SCADA, EMS and DCS compared SystemWhat it doesWho decides SCADACollects data across sites, shows it, raises alarms, passes commandsThe operator, with automation for alarmsEMSCalculates setpoints for batteries, PV and loads within site, market and grid limitsSoftware, automaticallyDCS (distributed control system)Runs continuous closed-loop control of one process plantControllers, under operator supervision ## What SCADA means for your software Whether you buy a SCADA system, build a monitoring platform or connect an EMS to an existing SCADA, the same issues decide the cost and the risk. Requirements worth writing into the specification: - A signal list comes first. Every device model needs its register or point map, units, scaling and naming. Agree on the tag naming convention before integration starts; renaming thousands of signals later is expensive. - Time is part of the data. Store timestamps from the source in UTC, record whether a value is measured, estimated or stale, and handle daylight saving changes in displays. - Alarms follow a written philosophy. Each alarm has a priority, a clear text and an action. A screen that shows hundreds of active alarms trains operators to ignore them. A device that stops reporting is an alarm of its own. - Commands are controlled. Writes to equipment require a role with the right permission and a confirmation, are read back from the device and are logged with who sent them and why. - The HMI is designed for the control room. Operators read it all day and react in seconds, so it needs a conservative palette tied to statuses, a schematic that shows where a fault is, and no decoration that competes with live data. - Control never depends on the cloud. Local controllers and safety functions keep working when the connection to the platform is lost; the cloud receives data and sends configuration, never real-time control. - The OT network is separated from IT and the internet. Remote access goes through a controlled path with multi-factor authentication, and every change to the system is recorded. Writing the specification? Add SCADA to your requirements checklist Collect the terms your project touches and get their system requirements in one e-mail, ready for an RFP. ## Rules and standards Electricity companies in the EU that are large enough fall under NIS2, Directive (EU) 2022/2555. Electricity undertakings, distribution and transmission system operators, producers and market participants providing aggregation, demand response or energy storage services are all listed in Annex I. Article 21 requires them to take cybersecurity risk-management measures, including incident handling, supply chain security, access control and multi-factor authentication, and SCADA is usually the system where those measures matter most. NIST Special Publication 800-82 Rev. 3, the Guide to Operational Technology Security, is a widely used reference for securing SCADA and other operational technology. It covers network segmentation, remote access, patching where downtime is costly and monitoring of control networks. The IEC 62443 series sets security requirements for industrial automation and control systems and their suppliers, and buyers often ask vendors to show how they meet it. ## From our projects For [Kyoto Group](https://ordergroup.co/case-studies/kyoto-digital-twin-software/) we spent three and a half years on software for a molten-salt thermal energy storage plant, which grew into a SCADA-based system that monitors and controls the flow of energy in real time. Our scope included control of the thermal store integrated with the plant's SCADA layer, surveillance with infrared cameras and image recognition working alongside it, and augmented reality elements in the operator's camera view that present key plant data. The lessons on the data platform and access control from the same project are under [digital twin](https://ordergroup.co/glossary/digital-twin/); the one that applies to any SCADA project is to design operator roles at the start. On [Skyfri's](https://ordergroup.co/case-studies/skyfri-solar-asset-management-platform/) platform SCADA and EMS are separate layers. Skyfri's own SolarSCADA handles site-level hardware control and monitoring, and the EMS we designed and built holds the control logic for charging, discharging, peak shaving, trading and export limits, running fully offline at each site. For Global Green's battery storage sites we added an alarm for a battery in the off state in July 2026, and as of October 2026 we are separating batteries and meters in the web monitoring. From our projects [KYOTO - Industrial IoT & Digital Twin for Thermal Energy Storage Why our team flew to Oslo every two weeks: the story of KYOTO's industrial IoT and digital twin project for thermal energy storage, and its results.](https://ordergroup.co/case-studies/kyoto-digital-twin-software/) Where to get it - [Skyfri](https://skyfri.com/product) Skyfri offers SolarSCADA and an energy management platform for solar and battery sites. We designed and built the EMS that works alongside its SCADA. ## Related terms - [Digital twin](https://ordergroup.co/glossary/digital-twin/) A digital twin is a software representation of a physical asset or process, kept in sync with it through live data, so operators can monitor it, simulate changes and sometimes control it without touching the real equipment. - [EMS](https://ordergroup.co/glossary/ems/) Energy management system An energy management system (EMS) is software that reads the meters, inverters and batteries on a site and sends them setpoints, deciding when to charge, discharge, curtail or trade within grid, contract and safety limits. - [Modbus](https://ordergroup.co/glossary/modbus/) Modbus is an open request-response protocol for reading and writing 16-bit registers and single bits in field devices. Inverters, batteries and energy meters use it over serial lines (Modbus RTU) or Ethernet (Modbus TCP). - [NIS2](https://ordergroup.co/glossary/nis2/) NIS2 Directive NIS2 is the EU cybersecurity directive (EU) 2022/2555. It requires essential and important entities, including electricity suppliers, grid operators, producers, aggregators, storage and charge point operators, to manage cyber risk and send an early warning of significant incidents within 24 hours. - [Thermal energy storage](https://ordergroup.co/glossary/thermal-energy-storage/) Thermal energy storage (TES) stores energy by heating or cooling a medium such as water, rock or molten salt, and releases it later as heat, cold or power. It lets a site buy electricity when it is cheap and deliver heat when it is needed. ## Read more on the blog - Article [Battery Energy Storage System (BESS): How It Works and What Software It Needs](https://ordergroup.co/blog/battery-energy-storage-system/) - Article [What Does BMS Mean? Battery & Building Management Systems Explained](https://ordergroup.co/blog/what-is-bms/) - Article [Fixing Common Issues with a Digital Twin](https://ordergroup.co/blog/digital-twin-troubleshooting/) - Article [Energy Trading Platforms: How They Work, Main Types and the Software Behind Them](https://ordergroup.co/blog/energy-trading-platforms/) ## Sources 1. [NIST SP 800-82 Rev. 3, Guide to Operational Technology (OT) Security](https://csrc.nist.gov/pubs/sp/800/82/r3/final) - NIST 2. [Directive (EU) 2022/2555 (NIS 2 Directive), Article 21 and Annex I](https://eur-lex.europa.eu/eli/dir/2022/2555/oj/eng) - EUR-Lex Michał Dżaman reviewed this entry. Ask how it applies to your project. [Ask an engineer](https://ordergroup.co/contact-us/) ## FAQ ![Michał Dżaman](https://ordergroup.co/media/images/T02DHCC1Z-USU629221-c8b7d6d66b56-512.format-webp.webp) Michał Dżaman Co-founder & Head of Backend [Talk to an engineer](https://ordergroup.co/contact-us/) ### What is the difference between SCADA and an EMS? SCADA collects data, shows it to operators and passes on their commands. An EMS calculates what batteries, solar plants and loads should do and sends the setpoints itself. Many sites run both: SCADA for visibility and manual control, the EMS for automatic decisions. ### Can SCADA run in the cloud? Monitoring, history and analytics can. Real-time control and safety functions should stay on site, on controllers and servers that keep working when the internet connection drops. A common design sends data to the cloud and keeps commands local. ### Which protocols does a SCADA system use? At device level most often Modbus RTU or Modbus TCP. Grid and substation equipment uses IEC 60870-5-104, DNP3 or IEC 61850, and OPC UA connects SCADA to other systems. The list for your site depends on the devices you have, so collect it before you estimate the integration. ### Is a SCADA system covered by NIS2? NIS2 applies to organizations, not to products. If your company is an essential or important entity, for example an electricity producer, grid operator or storage operator above the size thresholds, its SCADA falls under the Article 21 risk-management measures, and suppliers of the system should expect to be asked to support them. Building a system that depends on SCADA? See how we build software for this domain, with case studies and the stack we use. [See Energy Hub](https://ordergroup.co/energy-hub/) Requirements checklist For each term we send the definition and what it requires from your software. Free, no sales call needed. Your checklist is empty. Use the plus next to a term to add it.