Configuration software is a control system composed of HMI (Human and Machine Interface) / MMI (Man and Machine Interface)/ SCADA (Supervisory Control and Data Acquisition). At present, the rapid development of configuration software has extended to enterprise information management system, management and control integration, remote diagnosis and maintenance and a series of data integration on the Internet.
With the appearance of distributed control system (DCS), the concept of "configuration" is well known by the majority of production process automation technicians.
In the process of continuous development and application of industrial control technology, PC (including industrial computer) has more advantages than the previous special system. PC technology has maintained a rapid development speed, and a variety of related technologies have been mature.
Industrial control system built by PC has relatively low cost of ownership and PC has rich software and hardware resources, strong interoperability between software and PC based control system is easy to learn and use, and users can easily get technical support.
In the penetration of PC technology into the field of industrial control, configuration software occupies a very special and important position.
Configuration software refers to some special software for data acquisition and process control. They are the software platform and development environment at the monitoring level of automatic control system. They use flexible configuration mode to provide users with general software tools for quickly building the monitoring function of industrial automatic control system. Configuration software should support all kinds of industrial control equipment and common communication protocols, and usually provide distributed data management and network functions.
Compared with the original concept of HMI, configuration software should be a software tool or development environment that enables users to quickly establish their own HMI.
Before the appearance of configuration software, users in the field of industrial control has to commission a third party to write HMI applications, which required long time, and was in low efficiency and poor reliability. Or users purchased special industrial control systems, which were usually closed systems, resulting in poor choices.
The purchased special systems often could not meet the needs, and it was difficult to interact with the outside world, upgrade and increase power. There are serious restrictions on the use of energy.
The invention of configuration software has freed users from these difficulties. Users can use the function of configuration software to build a set of most suitable application system.
With the rapid development of configuration software, real-time database, real-time control, SCADA, communication and networking, open data interface, extensive support for I / O equipment have become the main content of configuration software. With the development of technology, monitoring configuration software will continue to develop.
Figure 1: Components and structure of a configuration system
With the deepening of the application of industrial control system, people gradually realize that the original development method of upper computer programming is time-consuming and laborious for the project when facing the larger scale and more complex control system.
At the same time, the extensive application of management information system (MIS) and computer integrated manufacturing system (CIMS) require the industrial site to provide more detailed and in-depth data for the production, operation and decision-making of enterprises, so as to optimize the various links in the production and operation of enterprises.
Here are several configuration software.
The early InTouch software uses DDE mode to communicate with the driver, but the performance of this software is poor. The latest in touch 7.0 is completely based on the 32-bit windows platform, and provides OPC support.
Figure 2: InTouch software features.
Intel solution started with FIX configuration software. It was acquired by Emerson in 1995 and is now a wholly-owned subsidiary of Emerson group.
Fix6. X software provides familiar concepts and operation interface for industrial control personnel, and provides complete driver (to be purchased separately). Intel solution names its latest product series iFIX.
In iFIX, intel solution provides powerful configuration function, but the new version is not fully compatible with the previous 6. X version. The original script language is changed to VBA (Visual Basic for application), and Microsoft's VBA development environment is integrated inside.
Unfortunately, Intel solution cannot provide a tool to convert 6.1 scripting language to VBA. In iFIX, intellution's products are closely integrated with Microsoft's operating system and network. Intellution is also one of the founding members of OPC (OLE for process control). IFIX's OPC components and drivers also need to be purchased separately.
Figure 3: HMI/SCADA iFIX program interface on desktop and tablet.
Citect of CIT company has a simple way of operation, but it is more for programmers than industrial control users. Citect provides a script language similar to C language for secondary development, which undoubtedly increases the difficulty for users to carry out secondary development.
Figure 4: One control screen of HMI/SCADA Citect
WinCC of Siemens also has a complete set of configuration development environment. Simens provides C-like scripts, including a debugging environment. WINCC with built-in OPC support can configure the distributed system. But the structure of WinCC is more complex, so it is better for users to master the application of WinCC through the training of Siemens.
Figure 5: Screens of control features of Siemens WinCC HMI/SCADA.
Around 1993, Beijing 3D force control technology Co., Ltd. has developed its first version of force control which was still a version based on DOS and VMS. Later, with the popularity of windows 3.1, the company developed a 16 bit Windows version of force control. But until the birth of Windows 95 version of force control, the former force control was mainly used for some projects within the company. The 1.0 version force control of 32 bit has already been more advanced in architecture. One of its biggest features is its three layer structure based on real meaning distributed real-time database, and the structure is a configurable active structure.
During the period of 1999-2000, force control has made great progress. The latest version 2.0 has greatly improved its rich features, being easy to use, open and adding the number of I / O drivers. In many aspects of the design, force control can start from the perspective of Chinese users, that is, pay attention to practicality, without losing the specification of large software. In addition, the company has invested a lot of manpower in product training, user technical support and so on. I believe that in a relatively short period of time, force control software products will form a huge impact in the industrial control software industry.
Other common configuration softwares are Cimplicity of Ge, RSView of Rockwell, lookout of Ni, Wizcon of pcsoft and MCGS of general state software company of China. These softwares have their own characteristics.
Figure 6: Force control software and components.
All configuration software currently seen can accomplish similar functions. For example, almost all configuration software running on 32-bit windows platform adopts window structure similar to resource browser, and configures and edits various resources (equipment, label quantity, picture, etc.) in industrial control system.
These configuration software all provides a variety of data drivers, all using script language to provide secondary development functions. However, from the perspective of technology, various configuration software provides different methods to realize these functions. From these differences and the trend of PC technology, we can see the future development direction of configuration software.
Most configuration software provides a variety of data acquisition programs, and users can configure according to their own needs. However, drivers can only be provided by configuration software developers, or written by users according to some configuration software interface specifications, which is hard for users. OPC specification is proposed by OPC foundation. Based on Microsoft's OLE/ DCOM technology, OPC specification provides a complete solution for software component interaction and data sharing in distributed system.
In the system supporting OPC, the data provider acts as the server and the data requester acts as the client. The server and the client communicate through DCOM interface without knowing the internal details of the other party. Because COM technology is implemented at the binary code level, the server and client can be provided by different manufacturers.
In practical use, the data acquisition program as a server is often provided by the hardware equipment manufacturer along with the hardware, which can give full play to the full performance of the hardware. The configuration software can be well connected with the drivers of various manufacturers through OPC, so it fundamentally solves the problem that the special format driver lags behind the hardware update.
At the same time, configuration software can also be used as a server to provide data for other application systems (such as MIS). OPC has been supported by well-known foreign manufacturers, including Interlution, Siemens, GE, ABB, etc. With the popularity of configuration software and hardware equipment supporting OPC, using OPC for data acquisition will become a more reasonable choice when using configuration products.
Script language is an important means to expand the function of configuration system. Therefore, most configuration software provide script language. There are three ways to implement the script language. First, the built-in C / basic language is used. Second, Microsoft's VBA programming language is used. Third, a few configuration software use object-oriented script language. C / basic like language requires users to write scripts with statements similar to high-level language, and use the combination of function calls provided by the system to complete various system functions.
Microsoft's VBA is a relatively complete development environment. The configuration software using VBA usually uses Microsoft's VBA environment and component technology to realize the objects in the configuration system in the form of components.
The VBA program is used to access these objects.
Because visual basic is interpreted and executed, some syntax errors of VBA program may not be found until it is executed. The object-oriented scripting language provides the object access mechanism, and the objects in the system can be accessed through their properties and methods. It's easy for users to learn, master and extend script language, but it's more complex to implement.
Configuration environment provides users with the ability to add new functions to the system without changing the original system. The added functions may come from configuration software developers, third-party software providers or users themselves. The most common way to add functions is the application of ActiveX components. At present, only a few configuration software can provide complete ActiveX components to introduce functions and realize the access of introduced objects in script language.
Figure 7: Screen of functionality of ActiveX.
With the popularization of management information system and computer integrated manufacturing system, the application of production field data is not only data collection and monitoring.
In the process of production and manufacturing, a large amount of field data is needed to analyze and control the process to realize the adjustment and optimization of the production process.
Most of the requirements of the existing configuration software are only provided in the form of reports, or data is exported to external database through ODBC for other business system calls. In most cases, configuration software is still needed to be redeveloped to achieve.
With the increase of information demand in production decision-making activities, it can be predicted that the integration of configuration software with management information system or leadership information system will be more closely, and it is likely to appear in configuration software in the form of modules that realize data analysis and decision-making functions.
The production mode of modern enterprises has become international and distributed. Internet will be the basis of distributed production.
It is an important issue for all configuration software developers whether the configuration software can run from the original LAN to support Internet.
In a long period of time, the monitoring of industrial site through Internet in browser mode will stay in the monitoring stage in most applications, and the actual control function should be realized through more stable technologies, such as special remote client, ActiveX control provided by professional developers or Java technology.
With the improvement of the technology of automatic control integrated system with industrial PC as the core and the improvement of the engineering technicians using configuration software, the user's requirements for configuration software are not as focused on the picture as in the past, but some substantive application functions, such as software PLC, advanced process control strategy, etc.
Soft PLC is a control device based on PC open structure, which has the same characteristics as hard PLC in function, reliability, speed, fault finding and so on.
The standard industrial PC can be converted into a full-function PLC process controller by using software technology. Soft PLC combines the functions of switch control, analog control, mathematical operation, numerical processing and communication network of computer and PLC.
It controls the kernel through multi tasks, and provides powerful instruction set, fast and accurate scanning period, reliable operation and open structure which can connect various I / O systems and networks. Therefore, soft PLC provides the same functions as hard PLC, and also has various advantages of PC environment.
Figure 8: ABB PLC AI523 B0
At present, the products with great influence in the world include ISaGRAF software package of CJ international company in France, WinPLC of PCSoft International, Paradym-31 of Wizdom Control Intellution company and ProcessSuite of Moore Process Automation Solutions in the United States, InControl of Wonder ware Controls in the US, SoftPLC, etc.
With the requirements of high flexibility and high efficiency put forward by enterprises, the control scheme based on classical control theory can not meet this requirements. After the successful application of advanced control strategy represented by multivariable predictive control, advanced process control (APC) has been widely concerned by the process industry. APC is a kind of operation and control strategy which is implemented in dynamic environment based on model and fully utilizing computer capability to maximize the benefit of the factory.
The advanced control strategies include: double control and valve position control, pure lag compensation control, decoupling control, adaptive control, differential beat control, state feedback control, multivariable predictive control, reasoning control and soft measurement technology, intelligent control (expert control, fuzzy control and neural network control), etc. Intelligent control has become a hot spot in development and application.
Now many enterprises have invested in the implementation of advanced control in the automation system of the device. Many control software companies and DCS manufacturers abroad are competing to develop advanced control and optimization control engineering software packages.
According to the market data, an ethylene plant requires an investment of $1.63 million to implement advanced control, and the benefit is expected to be $6million / year after the implementation. From the above, it can be seen that the configuration software which can embed advanced control and optimal control strategy will be greatly welcomed by users.
The demand of users promotes the continuous progress of technology, especially in the configuration software. The future configuration software will provide configuration function and support ActiveX in a more powerful distributed environment. The configuration software is an open system which is strongly expanded, supporting OPC and other industrial standards. Besides, it has strong control function and can be accessed through Internet.
The broad sense of HMI is "an interface between user and machine to communicate and convey information, and for users to receive information".
For example, in a factory, we need to collect the temperature and humidity of each area of the factory and the status of the machines in the factory. By monitoring and recording these parameters through a single device, users can deal with some unexpected situations. This is a typical application of SCADA / HMI.
Figure 9: ESA HMI ERGO222
Generally speaking, the HMI system must be equipped with following basic capabilities:
Real time data trend display - display the captured data on the screen immediately.
Automatic recording of data - automatically storing data in a database for later viewing.
Trend display of historical data -- the visualization of data in the database.
Report generation and printing - convert data into report format, and print out.
Graphical interface control - the operator can directly control the machine and other devices through the graphical interface.
Alarm generation and recording - users can define some conditions for alarm generation. For example, if the temperature is too high or the pressure exceeds the critical value, the system will give an alarm to inform the operator.