Supervisory control and data collection systems (scada systems). Control system software Hardware software for supervisory control system tools

Classification of automated control system software. As we have already mentioned, in the typical architecture of a SCADA system, two levels are clearly visible:

· local controller level , interacting with the control object through sensors and actuators;

· operational management level a technological process, the main components of which are servers, workstations of operators/dispatchers, and workstations of specialists.

Each of these levels operates under the control of specialized software (software). The development of this software or its choice from the software currently offered on the market depends on many factors, primarily on the tasks being solved at a specific level. Distinguish basic And applied software (see Figure 5.1).

Figure 5.2 - Classification of control system software.

Basic The software includes various components, but the main one is the operating system (OS) of the software and hardware of the process control system. Each level of the process control system is represented by “its own” software and hardware: at the lower level we are talking about controllers, while the main technical means of the upper level is a computer. In accordance with this, the following classification appeared among specialists: built-in And desktop software.

Obviously, the requirements for embedded and desktop software are different. The controller in the control system, along with the functions of collecting information, solves the problems of automatic continuous or logical control. In this regard, it is subject to strict requirements regarding the reaction time to the state of the object and the issuance of control actions to the actuators. The controller must guaranteed respond to changes in the state of an object for given time.

Selection of operating system software and hardware top level The process control system is determined by the application task (general use OS or RTOS). But the most popular and widespread are various versions of the Windows OS. They are equipped with top-level software and hardware of automated process control systems, represented by personal computers (PCs) of varying power and configuration - workstations of operators/dispatchers and specialists, database servers (DB), etc.

This situation arose as a result of a number of reasons and trends in the development of modern information and microprocessor technologies.

Here are some of the main arguments in favor of Windows:

· Windows is very widespread in the world, including in Kazakhstan, and therefore it is easy to find a specialist who could support systems based on this OS;

· this OS has many applications that provide solutions to various problems of processing and presenting information;

· Windows OS and Windows applications are easy to learn and have a standard, intuitive interface;

· applications running under Windows support publicly available data exchange standards;

· systems based on Windows OS are easy to operate and develop, which makes them economical both in terms of support and during gradual growth;

· Microsoft is developing information technology (IT) for Windows at a rapid pace, which allows companies using this platform to “keep up with the times.”

It should also be taken into account that an integral part of the upper level of the automated process control system is a person, whose reaction time to events is non-deterministic and often quite long. And the real-time problem itself at the upper level is not so relevant.

For the operation of the control system, another type of software is required - application software(PPO). There are two known ways to develop application software for control systems:

· creating your own application software using traditional programming tools (standard programming languages, debugging tools, etc.);

· use of existing (ready-made) tools for application software development.

· Upper-level automated process control software (SCADA packages) are designed to create application software for monitoring and control panels implemented on various computer platforms and specialized workstations. SCADA packages allow, with a minimum amount of programming in simple language tools, to develop a multifunctional interface that provides the operator/dispatcher not only with complete information about the technological process, but also the ability to control it.

In their development, SCADA packages have gone the same way as software for programming controllers. At the initial stage (80s), hardware development companies created their own (closed) SCADA systems, capable of interacting only with “their” equipment. Since the 90s, universal (open) SCADA programs have appeared.

The concept of openness is fundamental when it comes to software and hardware for building multi-level automation systems. This will be discussed in more detail below.

Now on the Russian market there are several dozen open SCADA packages that have almost the same functionality. But this does not mean at all that any of them can be successfully adapted to a particular management system with the same effort (time and financial), especially when it comes to its modernization. Each SCADA package is unique in its own way, and its choice for a specific automation system, discussed in the pages of special periodicals for almost the past ten years, still remains relevant.

Below is a list of the most popular SCADA packages in Russia and Kazakhstan.

· Trace Mode/Trace Mode (AdAstrA) - Russia;

· InTouch (Wonderware) - USA;

· FIX (Intellution) - USA;

· Genesis (Iconics Co) - USA;

· Factory Link (United States Data Co) - USA;

· RealFlex (BJ Software Systems) - USA;

· Sitex (Jade Software) - UK;

· Citect (CI Technology) - Australia;

· WinCC (Siemens) - Germany;

· RTWin (SWD Real Time Systems) - Russia;

· SARGON (NVT - Automation) - Russia;

· MIK$Sys (MEPhI) - Russia;

· Cimplicity (GE Fanuc) - USA;

· RSView (Rockwell Automation) - USA and many others.

The order in which the packages are presented in the above list is fairly random. Only the very fact of the existence of a particular system is stated. It is proposed to proceed from the premise that a SCADA package exists if at least several dozen projects have already been implemented using it. The second premise is that there is no absolutely best SCADA system for all applications. SCADA is just a convenient tool in the hands of the developer, and its adaptation to a specific automation system is a matter of qualifications and experience.

Basic functions of SCADA systems. Software type SCADA intended for the development and operation of automated process control systems. It is reasonable to ask the question: what comes first – development or operation? And the answer in this case is clear - the primary thing is an effective human-machine interface (HMI), focused on the user, i.e., on operational personnel, whose role in management is decisive. SCADA is a new approach to human factor problems in control systems (top-down), focusing primarily on the person (operator/dispatcher), his tasks and the functions he performs.

This approach allowed us to minimize the participation of operators/dispatchers in process management, but left them with the right to make decisions in special situations.

What did the SCADA system give to developers? With the advent of SCADA, they received an effective tool for designing control systems, the advantages of which include:

· high degree of automation of the control system development process;

· participation in the development of specialists in the field of automated processes (programming without programming);

· real reduction in time, and, consequently, financial costs for the development of control systems.

Before talking about the functionality of SCADA software, it is proposed to take a look at the functional responsibilities of the operators/dispatchers themselves. What are these responsibilities? It should be immediately noted that the functional responsibilities of operators/dispatchers of specific technological processes and production facilities can be significantly different, and the concepts of “operator” and “dispatcher” themselves are far from equivalent. However, among the variety of these responsibilities it turned out to be possible to find common ones inherent in this category of workers:

· registration of the values of the main technological and self-supporting parameters;

· analysis of the received data and their comparison with daily shift assignments and calendar plans;

· accounting and registration of the causes of disruptions in the technological process;

· keeping logs, drawing up operational reports, reports and other documents;

· provision of data on the progress of the technological process and the condition of the equipment to higher services, etc.

Previously, in the control room (control room) there was a control panel (hence the control room). For installations and technological processes with several hundred control and regulation parameters, the length of the shield could reach several tens of meters, and the number of devices on them could be measured in many tens, and sometimes hundreds. Among these instruments were indicating (scale and pointer), and writing (in addition to the scale and pointer, also chart paper with a pen), and signaling. At a certain time, the operator, walking around the switchboard, recorded instrument readings in a log. This is how the problem was solved collection and registration information.

The devices servicing the adjustable parameters had devices for setting the controller's task and for switching from automatic control mode to manual (remote) control. Here, next to the instruments, there were numerous buttons, toggle switches and circuit breakers for turning on and off various technological equipment. This is how problems were solved remote control technological parameters and equipment.

Above the control panel (usually on the wall) there was a mnemonic diagram of the technological process with technological devices, material flows and numerous alarm lamps of green, yellow and red (emergency) colors depicted on it. These lamps began to flash when an emergency situation occurred. In particularly dangerous situations, it was possible to issue a sound signal (siren) to quickly warn all operating personnel. This is how problems related to alarm violations of technological regulations (deviations of current values of technological parameters from the specified values, equipment failure).

With the advent of computers in the control room/control room, it was natural to transfer some of the functions related to the collection, registration, processing and display of information, identification of abnormal (emergency) situations, maintaining documentation, reports to computers. Even during the time of the first control computers with monochrome alphanumeric displays, “pseudo-graphic” images were already created on these displays through the efforts of enthusiastic developers - the prototype of modern graphics. Even then, the systems provided collection, processing, display of information, input of commands and data by the operator, archiving and logging of the process progress.

I would like to note that with the advent of modern software and hardware automation tools, operator/dispatcher workstations operating on the basis of SCADA software, control panels and wall-mounted mimic diagrams have not sunk irrevocably into oblivion. Where this is dictated by expediency, switchboards and control panels remain, but become more compact.

The advent of digital computers, and then personal computers, involved programmers in the process of creating an operator interface. They have good computer skills, programming languages, and are able to write complex programs. To do this, the programmer only needs an algorithm (a formalized scheme for solving a problem). But the trouble is that the programmer, as a rule, does not own the technology and does not “understand” the technological process. Therefore, to develop algorithms, it was necessary to involve technologists, for example, automation engineers.

A way out of this situation was found in the creation of methods of “programming without real programming”, accessible to understanding not only by a programmer, but also by a process engineer. As a result, software packages for creating a human-machine interface (Man/Humain Machine Interface, MMI/HMI) appeared. Abroad, this software was called SCADA (Supervisory Control And Data Acquisition - supervisory/dispatcher control and data acquisition), as it was intended for the development and functional support of operator/dispatcher workstations in automated process control systems. And in the mid-90s, the abbreviation SCADA confidently appeared in the vocabulary of Russian automation specialists.

It turned out that most of the tasks facing the creators of top-level software for automated process control systems in various industries can be easily unified, because the functions of the operator/dispatcher of almost any production are quite unified and can be easily formalized.

Thus, the basic set of functions of SCADA systems is predetermined by the role of this software in control systems (HMI) and is implemented in almost all packages. This:

· collection of information from lower-level devices (sensors, controllers);

· receiving and transmitting operator/dispatcher commands to controllers and actuators (remote control of objects);

· network interaction with the enterprise information system (with higher-level services);

· display of process parameters and equipment status using mnemonic diagrams, tables, graphs, etc. in a form that is easy to understand;

· notifying operating personnel about emergency situations and events related to the controlled technological process and the functioning of software and hardware of automated process control systems with recording of personnel actions in emergency situations.

· storage of received information in archives;

· presentation of current and accumulated (archived) data in the form of graphs (trends);

· secondary processing of information;

· generation of summaries and other reporting documents using templates created at the design stage.

There are several fundamental requirements for an interface created on the basis of SCADA software:

· it should be intuitive and convenient for the operator/dispatcher;

· a single operator error should not cause the issuance of a false control command to the object.

2.1 SCADA systems: general concepts and structure.

Dispatching ensures the coordinated operation of individual parts of the managed object in order to increase technical and economic indicators, rhythm of work, better use of production capacity, control in order to prevent the occurrence of emergency situations. The system allows you to keep operational records of energy consumption and control the parameters of engineering equipment.

When the equipment is located without permanent maintenance personnel or in another remote location, there is a need for remote monitoring and control from a central control center. It is also necessary to maintain records of the condition of the equipment, deviations from the norm of its parameters with the possibility of further archiving and viewing data for any period of time.

Control systems that allow the implementation of remote monitoring and control functions are called building management systems or dispatch systems.

The following systems are subject to dispatching:

Power supply and electric lighting;

Fire fighting equipment and fire extinguishing devices;

Ventilation and air conditioning;

Heating and hot water supply;

Sewerage and drainage systems;

Gas distribution points and stations.

It should be noted that the dispatch system is a superstructure over local automation, since the main tasks of managing engineering

equipment will be performed regardless of the operation of the system

dispatching.

Communications between system elements can be made using a variety of technologies, using various types of communication interfaces - both wired and wireless.

A significant advantage of dispatch systems is the support of several communication interfaces (protocols), and in cases of joint use with equipment from other manufacturers, there is the possibility of further expansion of the system without being tied to specific equipment.

It is often necessary that information about events that require attention and

rapid response of service personnel, reached, in addition to the control center, people who directly service the system, who do not always have a personal computer at hand. In this case, in addition to transmitting data to the control center, information via SMS can be transmitted directly to a mobile phone.

A full-fledged dispatch system usually immediately includes a dispatch server - a specially dedicated computer on which the SCADA system is installed.

SCADA is an acronym for Supervisory Control Data Acguistion. SCADA is software that performs the following functions:

Collection of data on the condition of engineering equipment from controllers of local automation panels;

Storage and display of information about the operation of equipment for the entire period of its operation;

Notifying service personnel about events requiring attention via e-mail, SMS or fax;

Access to control and management of equipment via the facility’s local network, via the Internet, etc.

A dispatch server with a SCADA system installed on it is often called the “top level”.

The SCADA system has the ability to expand/merge with other control systems.

2.2 Functional structure of SCADA.

Remote Terminal Units (RTU). Communication channels (CS). Control towers (MTUs). OS. Application software. Central control point.

SCADA Supervisory Control And Data Acquisition is the main and currently remains the most promising method of automated control of complex dynamic systems (processes) in vital and critical areas from the point of view of safety and reliability. It is on the principles of dispatch control that large automated systems are built in industry and energy, transport, space and military fields, and in various government agencies.

Over the past 10-15 years, interest in the problems of building highly efficient and highly reliable dispatch control and data collection systems has sharply increased abroad. On the one hand, this is due to significant progress in the field of computer technology, software and telecommunications, which increases the capabilities and expands the scope of application of automated systems. On the other hand, the development of information technology, an increase in the degree of automation and the redistribution of functions between a person and equipment has exacerbated the problem of interaction between a human operator and a control system. Investigation and analysis of the majority of accidents and incidents in aviation, land and water transport, industry and energy, some of which led to catastrophic consequences, showed that while in the 60s human error was the original cause of only 20% of incidents (80%, accordingly, due to technological malfunctions and failures), then in the 90s the share of the human factor increased to 80%, and, due to the constant improvement of technology and increased reliability of electronic equipment and machines, this share may increase further (Fig. 1)

Fig.1. Trends in the causes of accidents in complex automated systems

The main reason for such trends is the old traditional approach to the construction of complex automated control systems, which is often used today: a focus primarily on the use of the latest technical (technological) achievements, the desire to increase the degree of automation and functionality of the system and, at the same time, , underestimation of the need to build an effective human-machine interface (HMI Human-Machine Interface), i.e. user (operator) oriented interface. It is no coincidence that specifically for the last 15 years, i.e. The period of the emergence of powerful, compact and inexpensive computing tools marked the peak of research in the United States on human factor problems in control systems, including optimization of the architecture and HMI interface of supervisory control and data acquisition systems.

The study of materials on the problems of building effective and reliable dispatch control systems showed the need to use a new approach when developing such systems: human-centered design (or top-down, top-down), i.e. focusing primarily on the human operator (dispatcher) and his tasks, instead of the traditional and widely used hardware-centered (or bottom-up, bottom-up), in which, when building a system, the main attention was paid to the selection and development of technical means (equipment and software). The use of a new approach in real space and aviation developments and comparative tests of systems at the National Aeronautics and Space Administration (NASA), USA, confirmed its effectiveness, allowing to increase the productivity of operators, reduce procedural errors by an order of magnitude and reduce critical (non-correctable) errors to zero. ) operator errors.

SCADA is the process of collecting real-time information from remote points (objects) for processing, analysis and possible management of remote objects. The requirement for real-time processing is due to the need to deliver (issue) all necessary events (messages) and data to the central interface of the operator (dispatcher). At the same time, the concept of real time differs for different SCADA systems.

The prototype of modern SCADA systems in the early stages of development of automated control systems were telemetry and alarm systems.

All modern SCADA systems include three main structural components (see Fig. 2) Remote Terminal Unit (RTU) - a remote terminal that processes the task (control) in real time. The range of its implementations is wide, from primitive sensors that collect information from an object to specialized multiprocessor fault-tolerant computing systems that process information and control in hard real time. Its specific implementation is determined by the specific application. The use of low-level information processing devices makes it possible to reduce the bandwidth requirements for communication channels with the central control center.

Rice. 2. Main structural components of the SCADA system

Master Terminal Unit (MTU), Master Station (MS) control center (main terminal); carries out high-level data processing and control, usually in soft (quasi-) real time; One of the main functions is to provide an interface between the human operator and the system (HMI, MMI). Depending on the specific system, MTU can be implemented in a wide variety of forms, from a single computer with additional devices connecting to communication channels to large computing systems (mainframes) and/or workstations and servers integrated into a local network. As a rule, when constructing an MTU, various methods are used to increase the reliability and security of the system.

Communication System (CS) is a communication system (communication channels) required for transmitting data from remote points (objects, terminals) to the central interface of the operator-dispatcher and transmitting control signals to the RTU (or a remote object, depending on the specific design of the system).

Functional structure of SCADA

There are two types of control of remote objects in SCADA: automatic and initiated by the system operator.

Sheridan (Fig. 3) identified four main functional components of supervisory control and data collection systems: a human operator, a computer interacting with a person, a computer interacting with a task (object), a task (control object), and also identified five functions of a human operator in the system dispatcher control and characterized them as a set of nested loops in which the operator.

Rice. 3. Main structural components of SCADA systems

Plans what next steps need to be taken; trains (programs) the computer system for subsequent actions; monitors the results of (semi-)automatic operation of the system; intervenes in the process in the event of critical events when the automation cannot cope, or if it is necessary to adjust (adjust) process parameters; learns while working (gains experience).

This representation of SCADA was the basis for the development of modern methodologies for building effective dispatch systems.

2.3 Features of SCADA as a management process

Areas of application of SCADA systems

The main areas of application of dispatch control systems (according to foreign sources) are:

Electricity transmission and distribution management;

Industrial production;

Power generation;

Water intake, water treatment and distribution;

Production, transportation and distribution of oil and gas;

Transport management (all types of transport: air, metro, railway, road, water);

Telecommunications;

Military area.

Local control system

A local system is a set of equipment that is designed for local (local) management, protection, control, monitoring, collection and transmission of technological parameters of engineering equipment.

Local systems are completely independent systems and can operate in their own cycle without interaction with “top-level” systems.

The system consists of the following components:

Sensors;

Local controller/controllers;

Executive devices.

Sensors are designed to provide controllers with the necessary information about the condition of equipment. There are two types of sensors: discrete (relay), which can only transmit information of the type “Normal”, “Deviation”, and analog - which transmit the current value of the parameter. The local controller is a universal tool for processing and analyzing information from sensors, and managing, monitoring and storing information about the state of equipment. The controllers used can be either freely configurable, in which specific schemes for application and work with engineering equipment are already prescribed, or freely programmable, in which it is possible to program any algorithm for the operation of the device.

The main task of actuators is to control/change the operating parameters of engineering equipment. According to their purpose, actuators can be either regulating or protective.

Central control center

The Central Dispatch Center (hereinafter referred to as the CCC) is a hardware and software complex that performs the functions of collecting, processing and transmitting all the necessary information for the safe and reliable operation of facilities on which local systems are installed.

The Central Dispatch Center is intended for:

1. Prevention and remote identification of the cause of an accident or failure.

Dispatching allows you to prevent an emergency or damage to installed equipment. If the parameters of the process equipment go beyond the parameters, the system will promptly respond to the deviation and, depending on the priority level of the accident, will transmit to the control center a message about the parameter deviation with the ability to block the failed elements or turn them off. If an accident does occur, the operational team goes to the scene of the incident already knowing what happened and why, with the necessary tools, spare parts, and components. Ultimately, this will affect the speed of troubleshooting.

2. Assisting service personnel in making operational decisions.

Dispatching allows you to avoid hasty actions by personnel and remotely accurately plan a set of operational activities of station personnel before the arrival of the service team.

3. Minimizing the influence of the human factor in an emergency. When an alarm occurs, personnel often take hasty action to prevent an accident, and if the cause is not correctly identified, this can lead to serious consequences and long-term disruption.

4. Accounting for consumed energy resources. The complex is designed for recording, archiving and transmitting information in real time about the consumption of natural gas, heat, cold and hot water and electricity. EXO4 is dispatch system software. EXO4 has a graphical user interface. All settings and commands are performed using the keyboard and mouse.

The software is supplied only together with the corresponding hardware key, which is designed in the form of a USB key or a board that is inserted into a free PCI slot on the computer.

EXO4 and the EXO system perform the following functions:

Dynamic visualization of objects and processes;

Management and monitoring of objects;

Remote reading of alarms and data;

Multi-user system with authorization and control structure

by users;

Event registration and management;

Tracking accidents and conditions (4 levels of emergency priorities);

Creation of reports and reports on accidents and malfunctions;

Confirmation, blocking and unblocking of emergency messages;

Sound and visual support of emergency messages;

Redirecting alarm messages to one or more printers in

depending on time and (or) event;

Construction of graphs and trends (points) in real time;

Data and archiving management;

Network communication using client-server technology and support for various

protocols;

Tooltips;

Temporary programs;

Multi-window interface;

Database management;

Supports wired and wireless data transfer devices;

Automatic transition to winter and summer time;

System synchronization.

The user is provided with a convenient, intuitive graphical interface. Management and visualization of all engineering equipment can occur both using mnemonic diagrams and with the help of animation, graphs, using photographs and histograms.

Communication lines

The concept of communication lines refers to systems for transmitting and receiving information using various technical means.

Depending on the method of transmitting information, a distinction is made between wired landline communications (via the transmission of information packets over telephone lines) and mobile radio communications (via a radio signal).

Wired telephone services are provided by both state-owned companies and some commercial operators.

When using wired communications, the optimal solution is to use secure communication channels, also called VPN channels. Information transmitted through such channels is encoded with special hardware and cannot be used by third-party users. It is also possible to protect channels by using communication only between channel endpoints. There are three connection options: using a dedicated Ethernet line or broadband ADSL connection (using the Internet) and via a dial-up telephone connection using telephone modems. Each of the above options depends on the technical capabilities of the operator in a particular region.

Mobile radio services are provided exclusively by commercial Operators. Data transmission methods are similar to wired transmission with the only difference that instead of dial-up connections, base stations of the service operator are used. At the same time, it is possible to order a certain amount of received and transmitted information per calendar month or pay upon use for each month of service provision.

When choosing a communications service provider, you need to know whether the operator has a full set of permits and licenses for all types of activities carried out, and also has certificates of conformity for all supplied systems and communications equipment.

2.4 Trends in the development of technical means of dispatch control systems

General trends

Progress in the field of information technology has led to the development of all 3 main structural components of the dispatch control and data acquisition systems RTU, MTU, CS, which has significantly increased their capabilities; Thus, the number of controlled remote points in a modern SCADA system can reach 100,000.

The main trend in the development of technical means (hardware and software) of SCADA is migration towards completely open systems. The open architecture allows you to independently select different system components from different manufacturers; as a result, increased functionality, easier maintenance and reduced cost of SCADA systems.

Remote Terminal Units (RTU)

The main trend in the development of remote terminals is increasing processing speed and increasing their intellectual capabilities. Modern terminals are built on the basis of microprocessor technology, operate under the control of real-time operating systems, are, if necessary, combined into a network, and interact directly or through a network with intelligent electronic sensors of the controlled object and upper-level computers.

The specific RTU implementation depends on the application. These can be specialized (on-board) computers, including multiprocessor systems, ordinary microcomputers or personal computers (PC); for industrial and transport systems, there are two competing directions in RTU technology: industrial (industrial) PCs and programmable logic controllers (in Russian translation the term industrial controllers is often used) PLC.

Industrial computers are, as a rule, software compatible with conventional commercial PC machines, but adapted for harsh operating conditions, literally for installation in production, workshops, gas compressor stations, etc. Adaptation applies not only to design, but also to architecture and circuitry, since changes in ambient temperature lead to drift in electrical parameters. As interface devices with the control object, these systems are equipped with additional expansion cards (adapters), of which there is a wide variety on the market from various manufacturers (as well as the suppliers of industrial PCs themselves). Windows NT is increasingly being used as an operating system in industrial PCs operating as remote terminals, including various real-time extensions specially developed for this operating system (see below for more details).

Industrial controllers (PLC) are specialized computing devices designed to control processes (objects) in real time. Industrial controllers have a computing core and input/output modules that receive information (signals) from sensors, switches, converters, other devices and controllers, and control a process or object by issuing control signals to actuators, valves, switches and other actuators. Modern PLCs are often networked (RS-485, Ethernet, various types of industrial buses), and the software developed for them allows them to be programmed and controlled in a convenient form for the operator through a computer located at the top level of the SCADA system in the control room. (MTU). PLC market research has shown that controllers from Siemens, Fanuc Automation (General Electric), Allen-Bradley (Rockwell), and Mitsubishi have the most developed architecture, software and functionality. Also of interest are the products of CONTROL MICROSYSTEMS, industrial controllers for monitoring and control systems for oil and gas fields, pipelines, electrical substations, urban water supply, wastewater treatment, and environmental pollution control.

A lot of materials and research on industrial automation are devoted to the competition between the two areas of PC and PLC; Each of the authors provides a large number of arguments for and against each direction. However, a major trend can be identified: where increased reliability and hard real-time control are required, PLCs are used. This primarily concerns applications in life support systems (for example, water supply, electricity), transport systems, energy and industrial enterprises that pose an increased environmental hazard. Examples include the use of Simatic (Siemens) PLCs to control the power supply of a monorail in Germany, or the use of Allen-Bradley (Rockwell) controllers to modernize the outdated emergency ventilation and air conditioning control system at Plutonium Plant 4 at Los Alamos. PLC hardware allows you to effectively build fault-tolerant systems for critical applications based on multiple redundancies. Industrial PCs are used primarily in less critical areas (for example, in the automotive industry, modernization of production by General Motors), although there are examples of more critical applications (Warsaw metro, train control). According to experts, building PLC-based systems is usually a less expensive option compared to industrial computers.

Over the past 10-15 years, interest in the problems of building highly efficient and highly reliable dispatch control and data acquisition systems has sharply increased abroad. On the one hand, this is due to significant progress in the field of computer technology, software and telecommunications, which increases the capabilities and expands the scope of application of automated systems. On the other hand, the development of information technology, an increase in the degree of automation and the redistribution of functions between a person and equipment has exacerbated the problem of interaction between a human operator and a control system. Investigation and analysis of the majority of accidents and incidents in aviation, land and water transport, industry and energy, some of which led to catastrophic consequences, showed that while in the 60s human error was the original cause of only 20% of incidents (80%, accordingly, due to technological malfunctions and failures), then in the 90s the share of the human factor increased to 80%, and, due to the constant improvement of technology and increased reliability of electronic equipment and machines, this share may increase.

Definition and general structure of SCADA

The prototype of modern SCADA systems in the early stages of development of automated control systems were telemetry and alarm systems.

All modern SCADA systems include three main structural components:

Remote Terminal Unit (RTU) a remote terminal that processes a task (control) in real time. The range of its implementations is wide, from primitive sensors that collect information from an object to specialized multiprocessor fault-tolerant computing systems that process information and control in hard real time. Its specific implementation is determined by the specific application. The use of low-level information processing devices makes it possible to reduce the bandwidth requirements for communication channels with the central control center.

Master Terminal Unit (MTU), Master Station (MS) control center (main terminal); carries out high-level data processing and control, usually in soft (quasi-) real time; One of the main functions is to provide an interface between the human operator and the system (HMI, MMI). Depending on the specific system, MTU can be implemented in a wide variety of forms, from a single computer with additional devices connecting to communication channels to large computing systems (mainframes) and/or workstations and servers integrated into a local network. As a rule, when constructing an MTU, various methods are used to increase the reliability and security of the system.

Communication System (CS) a communication system (communication channels) is necessary for transmitting data from remote points (objects, terminals) to the central interface of the operator-dispatcher and transmitting control signals to the RTU (or a remote object, depending on the specific design of the system).

Functional structure of SCADA

There are two types of remote object management in SCADA:

automatic,
initiated by the system operator.

There are four main functional components of supervisory control and data acquisition systems:

human operator,
human interaction computer,
computer interaction with a task (object),
task (control object).

Functions of the human operator in a supervisory control system, as a set of nested loops in which the operator:

plans what next steps need to be taken;
trains (programs) the computer system for subsequent actions;
monitors the results of (semi-)automatic operation of the system;
intervenes in the process in the event of critical events when the automation cannot cope, or if it is necessary to adjust (adjust) process parameters;
learns while working (gains experience).

This representation of SCADA was the basis for the development of modern methodologies for building effective dispatch systems.

Features of SCADA as a control process

Features of the control process in modern dispatch systems:

The SCADA process is used in systems in which the presence of a person (operator, dispatcher) is required;
the SCADA process was developed for systems in which any incorrect influence can lead to failure (loss) of the control object or even catastrophic consequences;
the operator generally has overall responsibility for the control of the system, which, under normal conditions, only occasionally requires adjustment of parameters to achieve optimal performance;
active participation of the operator in the control process occurs infrequently and at unpredictable times, usually in the event of critical events (failures, emergency situations, etc.);
operator actions in critical situations can be strictly limited in time (several minutes or even seconds).

Basic requirements for dispatch control systems

The following basic requirements apply to SCADA systems:

system reliability (technological and functional);
management security;
accuracy of data processing and presentation;
ease of system expansion.

Security and reliability requirements for control in SCADA include the following:

no single equipment failure should cause the issuance of a false output action (command) to the control object;
no single operator error should cause the issuance of a false output action (command) to the control object;
all control operations must be intuitive and convenient for the operator (dispatcher).

Areas of application of SCADA systems

The main areas of application of dispatch control systems (according to foreign sources) are:

power transmission and distribution management;
industrial production;
power generation;
water intake, water treatment and distribution;
production, transportation and distribution of oil and gas;
management of space objects;
transport management (all types of transport: air, metro, railway, road, water);
telecommunications;
military area.

Currently, in developed foreign countries there is a real rise in the introduction of new and modernization of existing automated control systems in various sectors of the economy; In the vast majority of cases, these systems are built on the principle of supervisory control and data collection. It is characteristic that in the industrial sphere (in the manufacturing and mining industries, energy, etc.) the modernization of existing production facilities with new generation SCADA systems is most often mentioned. The effect of introducing a new management system is calculated, depending on the type of enterprise, from hundreds of thousands to millions of dollars per year; for example, for one average thermal station it is, according to experts, from 200,000 to 400,000 dollars. Much attention is paid to the modernization of industries that pose an environmental hazard to the environment (chemical and nuclear enterprises), as well as those that play a key role in the life support of populated areas (water supply, sewerage, etc.). Since the early 90s, intensive research and development began in the United States in the field of creating automated ground (vehicle) transport control systems ATMS (Advanced Traffic Management System).

Trends in the development of technical means of dispatch control systems

General trends

Progress in the field of information technology has led to the development of all 3 main structural components of the dispatch control and data acquisition systems RTU, MTU, CS, which has significantly increased their capabilities; Thus, the number of controlled remote points in a modern SCADA system can reach 100,000.
The main trend in the development of technical means (hardware and software) of SCADA is migration towards completely open systems. The open architecture allows you to independently select different system components from different manufacturers; as a result, increased functionality, easier maintenance and reduced cost of SCADA systems.

Remote Terminal Units (RTU)

The main trend in the development of remote terminals is increasing processing speed and increasing their intellectual capabilities. Modern terminals are built on the basis of microprocessor technology, operate under the control of real-time operating systems, are, if necessary, combined into a network, and interact directly or through a network with intelligent electronic sensors of the controlled object and upper-level computers.
The specific RTU implementation depends on the application. These can be specialized (on-board) computers, including multiprocessor systems, ordinary microcomputers or personal computers (PC); for industrial and transport systems, there are two competing directions in RTU technology: industrial (industrial) PCs and programmable logic controllers (in Russian translation the term industrial controllers is often used) PLC.

Industrial computers They are, as a rule, software compatible with conventional commercial PC machines, but adapted for harsh operating conditions, literally for installation in production, workshops, gas compressor stations, etc. Adaptation applies not only to design, but also to architecture and circuitry, since changes in ambient temperature lead to drift in electrical parameters. As interface devices with the control object, these systems are equipped with additional expansion cards (adapters), of which there is a wide variety on the market from various manufacturers (as well as the suppliers of industrial PCs themselves). Windows NT is increasingly being used as an operating system in industrial PCs operating as remote terminals, including various real-time extensions specially developed for this operating system (see below for more details).

Industrial controllers (PLC) are specialized computing devices designed to control processes (objects) in real time. Industrial controllers have a computing core and input/output modules that receive information (signals) from sensors, switches, converters, other devices and controllers, and control a process or object by issuing control signals to actuators, valves, switches and other actuators. Modern PLCs are often networked (RS-485, Ethernet, various types of industrial buses), and the software developed for them allows them to be programmed and controlled in a convenient form for the operator through a computer located at the top level of the SCADA system in the control room. (MTU). PLC market research has shown that controllers from Siemens, Fanuc Automation (General Electric), Allen-Bradley (Rockwell), and Mitsubishi have the most developed architecture, software and functionality. Also of interest are the products of CONTROL MICROSYSTEMS, industrial controllers for monitoring and control systems for oil and gas fields, pipelines, electrical substations, urban water supply, wastewater treatment, and environmental pollution control.

Communication channels (CS)

Communication channels for modern dispatch systems are very diverse; the choice of a specific solution depends on the system architecture, the distance between the control unit (MTU) and the RTU, the number of controlled points, the requirements for channel throughput and reliability, and the availability of available commercial communication lines.

The development trend of CS as a structural component of SCADA systems can be considered the use of not only a wide variety of dedicated communication channels (ISDN, ATM, etc.), but also corporate computer networks and specialized industrial buses.

In modern industrial, energy and transport systems, industrial buses have gained great popularity - specialized high-speed communication channels that make it possible to effectively solve the problem of reliability and noise immunity of connections at different hierarchical levels of automation. There are three main categories of industrial buses, characterizing their purpose (place in the system) and the complexity of the transmitted information: Sensor, Device, Field. Many industrial tires cover two or even all three categories.

Of the variety of industrial buses used around the world (about 70 types are installed in various systems in Germany alone), the industrial version of Ethernet and PROFIBUS should be highlighted, the most popular at present and, apparently, the most promising. The use of specialized protocols in industrial Ethernet allows one to avoid the inherent non-determinism of this bus (due to the CSMA/CD subscriber access method), and at the same time take advantage of its advantages as an open interface. The PROFIBUS bus is currently one of the most promising for use in industrial and transport control systems; it provides high-speed (up to 12 Mbaud) noise-resistant data transmission (code distance = 4) over a distance of up to 90 km. On the basis of this bus, for example, an automated train control system in the Warsaw metro was built.

Control towers (MTU)

The main trend in the development of MTUs (control towers) is the transition of most SCADA system developers to a client-server architecture, consisting of 4 functional components.

1. User (Operator) Interface(user/operator interface) is an extremely important component of SCADA systems. It is characterized by a) standardization of the user interface around several platforms; b) the ever-increasing influence of Windows NT; c) use of a standard graphical user interface (GUI); d) object-oriented programming technologies: DDE, OLE, Active X, OPC (OLE for Process Control), DCOM; e) standard application development tools, the most popular of which are Visual Basic for Applications (VBA), Visual C++; f) the emergence of commercial versions of SCADA/MMI class software for a wide range of tasks. Object independence allows the user interface to represent virtual objects created by other systems. The result is increased capabilities for optimizing the HMI interface.

2. Data Management(data management) a move away from highly specialized databases towards support for most corporate relational databases (Microsoft SQL, Oracle). Data management and report generation functions are carried out using standard SQL and 4GL tools; This data independence isolates data access and management functions from SCADA targets, allowing additional data analysis and management applications to be easily developed.

3. Networking & Services(networks and services) transition to the use of standard network technologies and protocols. Services for network management, security and access control, transaction monitoring, mail transmission, scanning of available resources (processes) can be performed independently of the target SCADA program code developed by another vendor.

4. Real-Time Services(real-time services) freeing the MTU from the load of the components listed above allows you to concentrate on the performance requirements for real-time and quasi-real-time tasks. These services are high-speed processors that manage the exchange of information with RTU and SCADA processes, manage the resident part of the database, notify about events, perform system management actions, and transfer information about events to the user (operator) interface.

Despite the ongoing debate among control systems specialists about which is better, UNIX or Windows NT? , the market clearly chose the latter. Decisive for the rapid growth of the popularity of Windows NT was its open architecture and effective application development tools, which allowed numerous development companies to create software products to solve a wide range of problems.

The growing use of Windows NT in automated control systems is largely due to the emergence of a number of software products that make it possible to use it as a platform for creating critical applications in real-time systems, as well as in embedded configurations. The most well-known real-time extensions for Windows NT are products from VenturCom, Nematron, and RadiSys.

VenturCom solutions have become the de facto standard for creating critical real-time applications on the Windows NT platform. When developing an interface for real-time applications, the company's developers took the path of modifying the Windows NT module of the hardware abstraction layer (HAL Hardware Abstraction Layer), which is responsible for generating high-priority system interrupts that interfere with the task of controlling in hard real time. VenturCom's Component Integrator software is a means of accelerating the development and implementation of real-time applications for Windows NT; it comes as an integrated package consisting of tools for creating embedded applications (ECK Embedded Component Kit) and actual real-time extensions (RTX 4.1), allowing applications created to run under Windows NT to run in real time.

RadiSys has taken a different approach to developing real-time extensions: Windows NT boots as a low-priority task under the well-tested and well-known real-time operating system iRMX for about 20 years. All real-time processing and control functions run as high-priority tasks under iRMX, isolated in memory from Windows NT applications and drivers by the processor's protection mechanism. This approach has the advantage over the VenturCom solution that the real-time task is independent of Windows NT: in the event of a crash or catastrophic system error in Windows NT, the real-time control task will continue to run. This solution allows you to inform the main task about problems that have arisen in the operation of NT, and reserve only the right to continue working or stop the entire system.

It should be noted that in SCADA systems the requirement of hard real time (i.e. the ability to respond/process events in clearly defined, guaranteed time intervals) applies, as a rule, only to remote terminals; in dispatch control units (MTU), events (processes, objects) are processed/managed in soft (quasi-) real time.

Application software

Focus on open architectures when building supervisory control and data acquisition systems allows the developers of these systems to concentrate directly on the target SCADA task of collecting and processing data, monitoring, event analysis, control, and implementing an HMI interface.

As a rule, target software for automated control systems is developed for a specific application by the suppliers of these systems themselves.

APCS software is a complex of various programs, the main task of which is to ensure the uninterrupted functioning of programmers, controllers, engineering stations and other computing tools as part of the system. There are two types of automated process control system software.

General - suitable for all technical means and is not tied to any one object. Combines SCADA and operating systems, as well as software packages.
Special - includes software solutions developed specifically for certain automated process control systems. Combines data archiving programs, software for controllers and information processing.

We offer to buy software for automated process control systems on favorable terms. On sale:

MasterSCADA systems,
MasterPLC for logic controllers,
OPC servers DA/HDA/UA for collecting and providing data,
engineering support station PID-expert.

Prices for individual items are shown in the price list. See product pages for detailed specifications. For additional information about the range of products, payment terms and delivery times, please contact the manager by phone.

SCADA system MasterSCADA

MasterSCADA is a SCADA system for process control systems, MES, accounting and dispatching tasks for industrial facilities, housing and communal services and buildings.

MasterSCADA™ is the most modern, innovative, powerful and convenient tool for fast and high-quality system development. This is software for control systems, which embodies twenty years of experience in product development for the automation of a wide variety of objects.

MasterSCADA™ is not just one of the modern SCADA- And SoftLogic-packages, this is a fundamentally new tool for developing automation and dispatch systems. It implements tools and methods for project development that provide a sharp reduction in labor costs and increase the reliability of the created system. Developing projects in MasterSCADA is easy and pleasant.

MasterSCADA 3.X MasterSCADA 3.X is the most popular domestic SCADA system. The popularity of MasterSCADA is confirmed by the assessments of many experts and surveys on specialized Internet portals. For example, MasterSCADA was recognized as Product of the Year by the Russian editors of the authoritative international magazine Control Engineering. More than 10,000 implementations have been implemented based on MasterSCADA 3.x. Among the implemented projects are global systems with more than 100,000 parameters coming to one survey server, and with more than 300 operator locations.

MasterSCADA 4D MasterSCADA 4D is a product of a new generation of SCADA systems. In it, compared to the previous version, the tools for creating large distributed systems with the ability to use Internet of Things technologies are significantly expanded, convenience and flexibility are increased, the ability to use various hardware platforms and operating systems is expanded, the number of supported levels of control systems is increased, and functionality is migrated between levels. MasterSCADA makes it easy to develop projects of any scale and complexity. For this purpose, various approaches are proposed that provide the most comfortable development conditions for each type of project.

SoftLogic system - MasterPLC

Execution systems for programmable logic controllers with open architecture (SoftLogic), based on x86, ARM7, ARM9, StrongARM, xScale platforms and DOS, miniOS7, Linux, Ecos, Windows CE, QNX, Windows operating systems.

Supports work with controllers:

ICP DAS ( I-7188, I-8000, Wincon, WinPAC, LinPAC, I-PAC );
ADVANTECH ( ADAM-4500, ADAM-5510, UNO2000, ... );
MOXA ( UC7408 and other 7xxx series );
ARIES ( PLC100, PLC110, PLC304, PLC308 );
TREY;
and many others...