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2020/06/26 14:44:45

SCADA Supervisory Control And Data Acquisition

SCADA system — a hardware and software system of data collection and dispatching control. The sense put in the term SCADA changed together with development of technologies of automation and management of technology processes. In the 80th years understood hardware and software systems of data collection of real time as SCADA systems more often. From 90th years the term SCADA is more used for designation only of a program part of the APCS interface (automatic management system by technology processes).

Content

The SCADA systems are actively used for dispatching control in the industry and power

Appointment and problems of SCADA systems

Are intended to SCADA system for implementation of monitoring and dispatching control of a large number of remote objects (from 1 to 10000, sometimes at distance in thousands of kilometers from each other) or one geographically distributed object. Oil pipelines, gas pipelines, water supply systems, electrodistribution substations, water intakes, diesel-generator points, etc. belong to such objects.

The main task of SCADA systems is collection of information about a set of remote objects, arriving from control points, and display of this information in the uniform dispatching center. Also, SCADA system should provide long-term archiving of data retrieveds. The manager often has potential not only to watch passively an object, but also to manage it to them, reacting to different situations.

Problems of SCADA systems:

  • data exchange with USO (communication devices with an object, i.e. with industrial controllers and payments of input-output) in real time via drivers;
  • information processing in real time;
  • information display on the monitor screen in a form, clear for the person;
  • database maintenance of real time with technology information;
  • alarm signaling and management of disturbing messages;
  • preparation and generation of reports on the course of technology process;
  • ensuring communication with external applications (DBMS, spreadsheets, word-processors, etc.).

Structure of SCADA systems

Structure of the SCADA system

Any SCADA system includes three components: the remote terminal (RTU – Remote Terminal Unit), a dispatcher station of management (MTU – Master Terminal Unit) and communications system (CS – Communication System).

The remote terminal is connected directly to a controlled object and exercises real-time control. As such terminal can serve as the primitive sensor performing an information retrieval from an object and the specialized multiprocessor failsafe computer system exercising information processing and real-time control.

The dispatcher station of management exercises data processing and control of the high level, as a rule, in the mode of kvazirealny time. It provides the human-computer interface. MTU can be as the single computer with additional devices of connection to communication channels, and the big computing system or a local network of workstations and servers.

The communications system is necessary for data transmission with RTU on MTU and back. As communications system the following data transmission channels can be used: dedicated lines, radio networks, analog telephone lines, ISDN networks, cellular networks GSM (GPRS). Often devices are connected to several networks for ensuring reliability of data transmission.

Features of management process in SCADA systems

  • In the SCADA systems presence of the person is obligatory (the operator, the manager).
  • Any wrong influence can lead to failure of a control object or even to catastrophic effects.
  • The manager bears, as a rule, the shared responsibility for system management which, under normal conditions, only occasionally requires fine tuning of parameters for achievement of optimum performance.
  • The manager passively watches the most part of time the displayed information. Active participation of the manager in management process happens infrequently, usually in case of approach of critical events - failures, emergency and emergency situations and so forth.
  • Actions of the operator in critical situations can be strictly limited on time (several minutes or even seconds).

Protection of SCADA systems

Among some users of the SCADA systems there is an opinion - if a system is not connected to the Internet, thereby it is insured from cyber attacks. Experts do not agree.

Physical isolation is useless against attacks on SCADA system, Faizel Lakhani, the expert in protection of information resources considers. According to him, physical isolation of systems is equivalent to fight against windmills[1].

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The majority of SCADA systems theoretically are isolated, however all of them are equally not completely disconnected from network. Besides, there are isolation bypass methods because of incorrect setup of systems, existence of test links or because someone configured Wi-fi Bridge. The management systems which are used at the enterprises of the electricity sector were created without security. They were developed for management of tension of electric current - and all this that they do to this day. The SCADA technology was based on the protocols which were outdate to present measures, and systems were initially created with a connectivity to each other, but not to the Internet. However everywhere the used TCP/IP protocol for the last 15 years reached also SCADA systems. In the Internet world practically everything is connected, so, cannot be considered as safe.

Faizel Lakhani, president of SS8 company
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Opinions of the Russian experts on security of the APCS and SCADA systems are conformable. As security issues of an APCS got to focus of general attention, some producers of protective solutions started product development, focused on opposition to threats for industrial information complexes (such products, in particular, the safe operating system - the environment for functioning only can be among the entrusted applications)[2].

Separate companies began to prepare analytical materials on these questions, making attempts to estimate a condition of an APCS in terms of security. Reaction to these initiatives from the specialists working with the industrial systems is ambiguous and is not always approving. The detached onlooker can draw a conclusion: between operators of an APCS and developers of means of information security there is a misunderstanding - producers try to create something specially under needs of owners and users of industrial information systems, but there is it not too successfully.

Anyway, the general opinion of expert community - a status of security of an APCS very weak. On the one hand, there are powerful managing subsystems which provide to the operator full control over production processes, including in strategic sectors of economy where any failures are dangerous, and on the other hand - at due skill and a share of carelessness from the company the person, very and very foreign can become this operator. It is a little practice on information security support on industrial enterprises, the management is inclined to revaluate security of an APCS, and to the companies working in the field of data protection real needs of this sector and the principles of functioning of industrial information systems are often unclear. Integrators and consultants can attract to creation of a system of their security not the broadest range of protective solutions that is promoted, considerably, by nonflexible policy of certification and not really active production of these products in Russia.

As modern HMI/SCADA of the solution can accelerate transition to the Industry 4.0

The most part of the data used by the industrial solutions IoT arrives from the software of automation of HMI/SCADA. How to accelerate transformation of production taking into account it? Technologies of automation, such as software of HMI/SCADA, exist many years. They were an incitement to what many call "the third industrial revolution". In 2020 when reach the next stage known as "the Industry 4.0", many companies reinterpret the future and try to understand how they can implement the advantages brought by digital transformation. Solutions for automation are the integral and key part of process, opening an era in which operational data are immediately analyzed using algorithms of artificial intelligence / machine learning. AI automatically optimizes transactions through "the closed circuit" or warns the person about further actions. HMI/SCADA allow to make more weighed decisions for quick response. Conversion of operational data to analytics which then can be used for process optimization brings true value for business, turning automation into a layer on which users can build the digital conversions. In fact, automation becomes a basis of strategy of digitization[3].

Digital conversion helps to lower costs

Risk assessment

Since launch of the operational[4]. producers face three main problems: how at the same time to increase availability, to manage risks and to cut down expenses. The ultimate goal - to provide optimum efficiency of assets for maximizing desirable results. Producers can use HMI/SCADA for improvement of visibility, optimization of transactions and improvement of quality and performance. A glance - operators know that is important and what actions will be correct for increase in efficiency and cost reduction. Originally it is necessary to go through a risks assessment stage. It includes process of assessment of criticality of all assets within business and exposure of assessment: high, average and low. Then analytical solutions provide the optimized plan allowing to cut down expenses and at the same time as appropriate to reduce risk of failure taking into account probabilities and effects. The recommendations issued by analytics return to process through the level of automation, HMI/SCADA, and in this case the operator will be able to check the recommended parameters before their sending to real process or directly in a PLC. This transformation of data is used for acceptance of more reasoned decisions, pro-activity and process optimization.

Why the modern software for automation matters

Eighty five percent of the data used by analytical tools, such as software of performance management of assets (APM) or software of management of transactions (OPM) arrive "from a field" (data of OT). Thus, the correct setup of level of automation is necessary for a decision making possibility in the Industry 4.0.

The main objective of the software for automation consists in providing to the operator a window in the application with symbolic circuits, representations of trends, representations of signals, alarms, etc. However new technologies do HMI/SCADA more powerful, simple in use and more "connected".

The mobility becomes more and more important. Now operators want to browse operational data where are, "in the field", and not just on site the operator. Crisis of COVID-19 showed, it is how important to work far off for maintenance of work of our crucial infrastructure enterprises.

People we want to get access to our personal information from any place and at any time using the smartphone; The Same treats technology or production data. The managing director of the plant who is en route or should be separated from business should have an opportunity to monitor the enterprise, being far from office.

Digital conversion not always means that everything should be in a cloud.

Many tools can be deployed on site as a part of solutions of the company on automation or managements of workflows which, in fact, become an edge node for the industrial Internet.

The software for management of digital workflows yields huge results and can be unrolled over the existing automation level, providing (almost) paperless installation.

Typical scopes vary from standard working procedures before maintenance procedures or bypasses of the operator.

Key factors

Digital conversion does not happen suddenly; it is a long way. As well as any travel, it should include a clear and achievable goal, whether it be financial, operational or any other. That the travel was successful – it is necessary to take the correct steps. It is recommended to take one step back, to return to aspects of IT and OT to define the main problems.

Will not be harmful to include in a command pair of external, fresh eyes to ask questions. For example, how it is possible to save on production losses to be more competitive? How it is possible to optimize maintenance strategies and to reduce a downtime? How to reduce risks and to increase performance?

As soon as the purposes are set, the following task - to make the plan of implementation. Many industrial facilities already began a way, without realizing it. But travel can also have difficulties. One of the key problems defined within the Industry 4.0 and Industrial Internet Consortium, is the functional compatibility. With the advent of such standards as OPC UA, it becomes a smaller problem. When OPC UA is applied to automation level, it not only provides connectivity, but also ensures the structured safety of data transmission. It is not possible to manage, analyze or optimize what is not visible. For the existing installations or infrastructures it is important to provide, lack of failures in production and operational technology in the course of digitization. Contrary to implementation of ERP systems, it is recommended to begin with small and to unroll a new system in an own rhythm.

Begin with an automation layer

The first step - to upgrade what exists, to estimate spaces and to begin creation on this assessment. Technologies of automation can help to reduce risk of failures and to become very valuable boundary node of deployment. These are the mature and checked technologies which can give new opportunities, guaranteeing that the application remains safe, available and compatible.

Thus, process of digital conversion should take into account to need of the user and guarantee that will influence the operator of change positively. The purpose consists in facilitating life to operators, engineers, production management, etc.

Modern HMI/SCADA can deliver content to any attached device - the PC, the smartphone, the tablet - providing tools which correspond to needs of the user. Mobile devices showed capability to increase efficiency, and recent researches showed that operators with mobile automated workplaces for 30% are more effective, than the operators using stationary devices.

Thus, if to consider a way of digital transformation - it begins with an automation layer.

The flexibility of level of automation helps to integrate all necessary data and can reduce a gap between the diverse systems at low costs with the speed and accuracy necessary for receiving complete idea of the application.

Due to automation use as the main part of digital conversion, there is an opportunity to take its many advantage.

SCADA systems directory and projects

Primary partition of the directory: SCADA

Notes