What is SCADA?

SCADA (Supervisory Control and Data Acquisition) is an abbreviation of the English term, which in Finnish means supervisory and control system and data collection. SCADA is a computer-based set of software and hardware used to monitor and control large distributed processes and systems in industries such as power plants, water utilities, oil rigs, transportation, and other similar industries.

What is a SCADA system?

The SCADA system, also known as the operator control system, consists of a system that includes control room display terminals, servers and data collection equipment. The system is also referred to as an HMI system, which comes from the English words Human Machine Interface, i.e. the user interface between the user and the machine.

But what exactly is a Scada control room?

Often, the SCADA control room consists of user workstations that can be used to monitor and control the process. Workstations or the system can also be used remotely using, for example, the remote desktop protocol. Modern SCADA applications also support browser-based management.

What does the control room do?

The purpose of the workstation is to visualize the process situation for the user and enable controls from its screen. For example, the system also provides the workstation with indications of error situations that require more attention.

This kind of situation can be, for example, a power outage in a certain area, to which the system can react automatically or it can require user action.

The workstation retrieves its data from the server, where the database for, for example, measurement data is located. Servers can also be duplicated. Duplication can be done, for example, by distributing the system's servers to, for example, different fire stations to improve usability.

In addition, servers can be connected to the SCADA system, which change information from different communication protocols into a form that the system can understand. Depending on the industry, the system can communicate with field devices using several different protocols. Various equipment in the process act as field devices and data producers, for example pumps, circuit breakers, RTU or PLC devices.  

SCADA's information security and firewalls

Firewall services are an integral part of the data security of SCADA systems. They act as the first line of defense by monitoring and limiting network traffic, thereby protecting critical industrial processes and infrastructure from unauthorized access and potential threats. A properly configured and updated firewall ensures that SCADA systems operate securely and efficiently, which is vital for the continuity of services critical to society. Get to know the Save LAN firewall service.

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Ease of production control and order management

Valvomo software is able to read the memory and registers of programmable logic with the help of a data network. In control systems, the division of work between the SCADA program and the logic program is done so that the logic control can manage the operation of the machine without the SCADA program at least until the end of the work sequence. When the product changes, a new program can be sent from the control room or settings can be changed for the next production piece.

The control rooms have versatile graphics tools, so it can be used to implement efficient graphical user interfaces (GUIs). The control room has the possibility to read the measurement through the logic as fast as the logic receives the measurement data. Modern communication channels and operating systems enable almost real-time monitoring of the process.

Factory control systems

Factory control systems are often divided into three or four hierarchical levels.

Level 1: Programmable logics, i.e. PLC devices

At the bottom are the programmable logics responsible for controlling the machines, i.e. PLC devices.

Level 2: Control software

At the next level are the control room software, which transfer information from the enterprise resource planning system (Enterprise Resource Planning ERP) at the top level of the control hierarchy, information related to production control in the form of recipes and set values for logics and reports in the other direction.

Level 3: MES

Between ERP software and control rooms, there can be MES (Manufacturing Execution System), i.e. the level of production control software, with which information is modified to be better suited to ERP systems.

Level 4: ERP

ERP enterprise resource planning system that controls production.

Valvomo software also collects implementation data and information necessary for quality control. These are moved up to the MES and ERP level as necessary. More extensive quality reports can remain only at the control room or MES levels.

Centralize different systems into one view

The SCADA system can be used to bring data from several different systems into one centralized view. This makes it easier to maintain the system because all information is available through one centralized system.

Information is also collected in the system using, for example, an RTU device. The purpose of this is to collect and summarize information from IED devices, which in the substation environment are mostly protection relays. There can be anywhere from a few to up to 30 IED devices under one RTU.

SCADA systems are used to improve process efficiency, improve equipment safety and save costs. They can also help businesses comply with rules and regulations.

SCADA vs DCS - what's the difference?

SCADA (Supervisory Control and Data Acquisition) and DCS (Distributed Control System) are two different automation systems used in industrial processes and infrastructure monitoring. Although both software systems are related to monitoring and control, their functions, application areas and features are different. Here is a comparison between SCADA and DCS:

Definition

SCADA: SCADA is a system that consists of a control room (or monitoring center) and remote points where process monitoring and control takes place. It collects, displays and analyzes real-time data from a wide monitored area.

DCS: DCS is a system that focuses on industrial process monitoring and control. It consists of decentralized control units that work together with the control center of the factory or process plant.

Architecture

SCADA: A SCADA system is usually hierarchical and centralized. The monitoring center is responsible for collecting, processing and displaying data, while the remote points transmit information from the facility's field devices to the monitoring center.

DCS: The DCS system is decentralized. Process control units are decentralized and are responsible for local monitoring and control. The DCS control center coordinates and connects these distributed units.

Areas of application

SCADA: SCADA systems are generally used to monitor larger infrastructures such as power plants, water supply, oil and gas industry, and traffic control.

DCS: DCS systems are used in process plants such as chemical industries, oil refineries, power plants and other industrial processes.

Data transfer

SCADA: A SCADA system usually uses standardized communication protocols such as IEC-104 or DNP3 to collect and transfer data between remote points and the monitoring center.

DCS: DCS systems often use the manufacturer's own communication protocols, which are optimized for fast and reliable communication between distributed control units and the monitoring center.

Operating environment

SCADA: SCADA systems are usually used in control rooms, where operators monitor the status of processes and can take manual actions if necessary.

DCS: DCS systems are used to automate and monitor the process and implement automatic control without constant human supervision.

As a result of the comparison, it can be stated that SCADA and DCS are both important industrial monitoring and control systems, but they are used in different application areas and their architecture and broad functionality differ from each other. SCADA systems are generally suitable for large-scale and distributed systems, while DCS systems are effective for automating and controlling a specific process in industrial plants.