Analysis of Status of Automatic Instrument and Control System

First, the basic status quo of automated instrumentation and control systems Into the 21st century, the rapid development of China's manufacturing industry has driven the demand for automated instrumentation and control systems. The advanced level of automation instruments and control systems used in large-scale projects in China is already in the world. Leading level. At present, the traditional manufacturing industry has passed a period of glory in developed countries, and its associated automation instruments have naturally grown slowly. The development of automated instrumentation The price issue in emerging markets affects instrument manufacturers from two perspectives. First, users in emerging markets are highly sensitive to product prices; second, they often find very cheap alternatives. Inspiring multinational companies to spend a lot of money on the development of new instruments.

Although the development of fieldbus technology in the important field of automation instrument technology development in the past 10 years has made remarkable achievements, it is still largely in the stage of replacing the analog transmission line in terms of application. In fact, the fieldbus is not only the change of the signal system, but also provides the basis for the informatization of the control technology. The user's demand for the transformation of the system's underlying information (control, diagnosis, and management) is the original driving force for fieldbus technology promotion. In recent years, the potential of fieldbus in equipment asset management, predictive diagnosis and smooth operation has begun to be excavated, showing a very promising development momentum.

However, based on the fieldbus technology networked control and distributed intelligent technology only, no significant breakthrough has occurred in theory or in practice at present. The speed bottleneck of fieldbus is sometimes not as good as the complex control and rapid response. Traditional instrumentation: The fieldbus battle that lasted for many years has not won a winner among manufacturers. It has also made users feel bored and consumed resources of various companies.

Some important windows in the world that reflect the trends of automated instrument products: International Instrument Exhibition represented by ISAEXPO, Miconix, etc., represented by ReadersChoiceAward (Reader's Choice Award). According to the reader selection award in the past three years, the award-winning products have not changed much. The focus of this year's development of automation instruments is on the application of meters.

This change in the development trend is very natural, and the digitized and intelligent instruments and systems have been told to develop in the past 10 years. Some problems have been accumulated in the application, and many innovative functions of smart meter design have not been fully applied. The main issues are the following.

(1) Information security and safety issues of digital instruments and systems (2) Reliability issues of microprograms and software.

(3) Confidentiality, security, and reliability of communications.

(4) When the smart meter is running, it can interact with the control system and how to interact.

(5) Smart meters provide much more information than analog meters and how to make full use of this information.

(6) Interoperability issues of many smart meters.

(7) Fault diagnosis of instruments and systems and interoperability issues of fault diagnosis information.

The above problems are all caused by digitization and networking. It is not that the existing technologies cannot solve these problems, but there are too many alternative solutions, and a unified solution is the most effective. And how to unify is currently being studied.

Although the speed of the introduction of new products for automated instruments has slowed down, the history of the development of automated instrument technology has continued, and the enthusiasm of the instrument manufacturers for the development of new technologies in the past two years is not high. However, the enthusiasm of meter users for the development of automation technologies is increasing. Recently, there have been eye-catching developments in the integration of information technology, instrument security technology, and wireless communication technology. In addition, the slowdown in the introduction of new foreign products has brought opportunities for the development of China's instrumentation. Domestic instruments have continued to develop in a healthy manner in the past two years. The overall trend of the industry and the introduction of the "2006-2007 Instrument Science and Technology Discipline Development Report" have not undergone major changes. Therefore, this report can also be considered as a supplement.

The six major concerns of ISAEXPO2008 are: information security, process automation, environmental and quality control, wireless and network communications, and enterprise integration. In fact, the major instrument exhibitions in the world, including China's Miconix exhibition, are the subject of the past two years. It can be said that these six aspects reflect the major developments in the field of automated instrumentation in the past two years. In six areas, information security, process automation and environmental control are mainly driven by technologies outside the field of automated instrumentation. The following sections of this report do not focus on it.

China Investment Advisory Network's "2009-2012 China Instrument Industry Investment Analysis and Prospects Forecast Report", in the introduction of the domestic instrumentation statement also justly expressed the lack of domestic automation instrumentation development, the discussion is this: Although China's instrumentation industry has a certain degree of development, it is far from being able to meet the growing needs of the national economy, scientific research, national defense construction, and social life. Most of China's instrumentation products belong to middle and low-end technology levels, and key indicators such as reliability and stability have not yet reached the requirements. Therefore, China needs to make long-term plans to use the revitalizing measurement control and instrumentation industry as a systems project to coordinate the major aspects of the measurement and control and instrumentation industry, including government, business, social environment, research, and educational institutions. Strategic measures and conscientiously implement them.

Second, the development trend of automated instrumentation and control systems (1) The development of automated instrumentation and enterprise information technology has brought two impacts on automation instruments: On the one hand, information technology and automation instruments compete for talents, and the climax of IT development. Many experienced instrumentation workers have turned to the IT industry. This is one of the reasons for the slowdown in the introduction of instrument products in recent years. On the other hand, automated instrumentation has used TI's mature technologies and products to accelerate the pace of information.

Informatization is the trend of the current era. Automation instrumentation technology includes such processes as information collection, information processing, and information application. Therefore, automation instrumentation technology is actually an important branch of information technology. The so-called enterprise integration is actually information integration and integration of the enterprise. The so-called information explosion actually obtains information over the ability of processing and application. One of the major obstacles for the obtained application is that the unity of information expression is not enough. How to improve the ability to process and apply information is the current topic.

Informatization requires physical things (including raw materials, equipment, products, control systems, meters, etc.) and production processes (including manufacturing methods, processes, etc.) in the real world. The company's management (including procurement, sales, logistics, etc.) is described by the computer's ability to identify and process 0s and 1s, then it is computed and processed by the computer, and finally the results of the processing are then reversed to the real world.

The premise of informatization is to convert the relationship between the real world and the things in the real world to 0 and 1. It cannot be achieved that this step of informatization cannot be achieved. This step is to establish an information model for the real world.

The information model is a set of simplified information. The abstract description of things by certain rules.

The definition of information model includes three elements: simplification, rules, and abstraction. The diversity of these three elements determines the diversity of possible information models. The process of establishing an information model includes the task of overcoming diversity and achieving unity. The goal of the automated instrumentation and system information model is to describe the information in an unambiguous manner to facilitate the exchange as a basic positioning and eventually achieve a wide range of interoperability.

In September 2006, at the Automation Forum of the IEC 100th Anniversary in Berlin, Germany, Prof. Diedrich, an IFAC expert, presented a report entitled "Information Model for Automated Factories", introducing different levels of control, different types of information at different stages of production. , different information processing technologies and tools.

The establishment of an information model is a basic task in the field of automated instrumentation, and it is also a method of administering only unified information. The main contents include: 1. Establish rules for describing things; 2. Describe the design of a large number of foods according to the rules. Create a model library.

Establishing the rules for describing things is a complicated research work, because with different cultural backgrounds, different religious beliefs, different descriptions of different things, and different levels of detail, there are many kinds of programs that are described. What we need is the current A program that is compatible with information processing capabilities and can be widely accepted by the public. Such programs often end up in the form of international standards. In the past two years, significant progress has been made in the formulation of such international standards.

The rules for describing things can be categorized into 3 categories according to their attributes:

(1) An information model for describing things. Such as the production of raw materials, components, control systems, production equipment, equipment, production process status, intermediate and final product content information model, this type of model to describe the basic attributes of the object, typically represented by IEC361987 industrial process Measurement and control process The data structure and element series in the equipment catalog and the standard data element type series standards related to IEC61360 and electronic component classification schemes.

(2) A model that describes the relationship between things (especially quantitative relationships). The important role of informatization is to optimize things. The condition for optimization is to understand the (quantitative) relationship between things. This model often appears as a mathematical model. Such models are often highly targeted and it is difficult to establish a uniform and widely used model, so they are less likely to appear in the form of international standards.

(3) Describe the object process information model. Such as production process, management process, typical representative is IEC62264 enterprise system integration series of standards.

In the establishment of information models for automated meters and applications, Chinese universities and research institutes have long studied. However, it has not positioned this work as an important foundation for informatization to promote industrialization, and it has always lacked national or industry level, comprehensive system planning and large-scale work.

China TC159 National Industrial Automation System and Integration Standardization Technical Committee and TC124 National Industrial Process Measurement and Control Standardization Technical Committee have done a lot of work in tracking and adopting international standards, except sending experts to join international standards working group to directly participate in the designation of international standards In addition, important information model standards have also been translated into national standards in a timely manner. With these methodological criteria for establishing an information model, the following workshops need to be done: propaganda, implementation, and learning methods. These methods are used to establish an interoperable information repository that is recognized and applied to the automation of the enterprise. .

Since the information model is still a new thing for domestic companies and engineers, these tasks are quite complicated at the initial stage. The most important thing is that China's manufacturing companies have less initiative to put forward the need for informationization. Therefore, China is relatively backward in this respect and urgently needs attention. .

(II) Integration of global information and life-cycle information of automated instrument engineering projects Global and full-life information integration is actually the full interoperability of automated instrument systems. Interoperability is hierarchical, and the most basic is the interoperability of the process controllers, which means that the control system and the field instrument surface are free of interoperability. The upper layer is the interoperability of the control system maintenance and diagnostic information of the production equipment. At the top level is the customer operation of corporate management information. Global information integration must at least achieve global information interoperability.

Different levels of implementation of interoperable technologies and methods are not exactly the same. The main technical history of the control system and field instrumentation layer: Kung-fu block, EDDL (electronic device description language), FDT/DTM (field device tool/device type manager), OPCUA (formerly Olefor ProcessControl, object linking and embedding for process control and control: Now Openness, Productivity Collaboration, Openness, Productivity and Collaboration, and corporate management rely partly on MES (Manufacturing Execution System) technology, which requires at the very least the integration of information exchange between layers of the enterprise.

From the demonstration to the completion and commissioning of the automation system engineer project and the overhaul and maintenance of the project, many technical documents will be produced at each stage of the entire process, and the documents at each stage are strongly related. These documents are now all in the form of computers in binary form. in. After applying a unified information model at each stage, the next phase of the document can have a good inheritance relative to the previous stage. For example, a control logic configuration diagram will be prepared during the engineering design phase of the project. If a unified information model is used, the system can be directly configured using this diagram during the startup commissioning phase. Full life cycle information integration is to achieve interoperability between the various stages of the system.

Such an information integration solution is provided by the user of the instrument. The user of the instrument is close to the production process and close to the application. Some user organizations put forward many requirements for the application of the automation instrument and established some group standards. Now they gradually translate these group standards into national standards, European standards or international standards, such as the requirements of the IEC 61242 process control engineering representation method for data exchange between PI diagrams and PID tools and PCE-CAE tools, and several parts of IEC 61987 ( PI, pipeline engineering and instrumentation; PID, pipeline engineering and instrumentation system diagram; PCE, process control engineering; CAE, computer-aided engineering).

The overall information integration project of the automation instrument engineering project and the whole life cycle is a long process. The introduction of the IEC62424 standard in the past two years is an important symbol in the development.

China has always had research institutes tracking the development direction of the information integration technology of the overall situation and the whole life cycle. When relevant standards documents are submitted by the technical organizations to the International Organization for Standardization, TC124 will quickly arrange experts to join the drafting working group. This tracking has continued for many years. Now. At the same time, TC124 also timely translated the published international standards into national standards.

The concept of information integration in the whole life cycle is relatively new to our engineers. Although some engineering projects use InTools, a tool software that can integrate information throughout the life cycle, people just put it in a certain life stage.

In China, the information integration of automated instrumentation in the system operation process is not enough. Fieldbus smart meters are used in time, and the data communication industry only serves as an alternative transfer function. The reason for this situation is that on the one hand, the demand for enterprise informationization by users in China is not urgent; on the other hand, we lack the effective information integration software that meets the actual conditions of various industries in China. The automation instrumentation workers do not have enough knowledge of what information can do. What benefits the user has for informationization are unclear, and there is no requirement for how to do it. These factors have affected the development of information integration technology.

Some people think that the development of smart meters represented by digitization and networking has three stages. The first stage is the digital field bus smart meters replacing analog instruments. The key is to play a role in saving installation costs and improving the performance of the instruments. The second stage is engineering and instrumentation. The integration of global information and life-cycle lifecycle information to achieve informationization focuses on improving the project engineering management level and operational efficiency. The third stage is the realization of so-called ubiquitous measurement, omnipresent networks, and wireless communication instrumentation as an important feature. Ubiquitous computing, real network control, the focus is to improve the overall efficiency of enterprises. The three-phase goal is quite ambitious and can be said to be the goal of the entire 21st century automation instrument. At present, the first phase of our country's work has been fully carried out, the second phase of the work started, and the third phase of the work is being explored.

(3) Functional safety and security is a very broad topic and this year's focus in the field of automation and instrumentation is on functional safety. IEC 61508 Electrical/Electronics/Departmental Programming The international standard for functional safety of electronic safety-related systems has been published since 1998. In 2003, the functional safety series of the IEC61511 process instrument safety system was published. In the past two years, China has published the functional safety of the series of national standards GB/T20438 electrical/electronic/technical programming related to the adoption of these international standards, and the functional safety of the GB/T 21109 process instrumentation safety system.

The important development of functional safety in the past two years has been the introduction of a large number of functional safety-certified instruments to the market. This has a great impact on the instrument market, so functional safety instrumentation is not only used in systems that have safety requirements, functional safety certification also plays a certain role in quantitative confirmation of instrument reliability, in order to compete in the favorable position In fact, practically all instrument manufacturers conduct functional safety studies.

Since the reliability engineering research of the instrument was carried out in the 20th century, the quality of instrument manufacturing has greatly improved. However, since the reliability data is obtained by the manufacturing companies themselves, the credibility of the users is low, so only a few companies have released the quantitative data of reliability. So reliability is empirical and ambiguous to the user. People are more willing to believe the brand.

The reliability engineering research in the 20th century has established a mature framework for the reliability design and processing of optical, mechanical, and electronic components. However, current instruments are almost all equipped with microprocessors, and the reliability of embedded programs and computer software has not yet been recognized as a method of obtaining quantitative data. The easiest thing to be puzzled here is: We all know that there are many errors in the Windows operating system, and most of our automated instrumentation system software is running evil in the Windows environment, so that we can believe that the automation system will have better than Windows. Reliability? Current functional security research and software reliability studies have provided some processing methods such as adding underlay programs, redundancy, fault tolerance, etc., allowing us to obtain reliable automated systems on unreliable Windows.

In IEC61508 and IEC61511, some methods are provided for the evaluation of the reliability and security of embedded programs and computer software. However, most of these contents are more principled, and it is not enough to rely heavily on the experience and level of design and evaluation of the assessors when implementing them. The demand in these areas has prompted all parties to increase the research on the reliability of embedded programs and computer software. From a programming language point of view, the functional safety of IEC61508-3 electrical/electronic/programmable electronic safety-related systems. Part 3: Software requirements for fully variable languages ​​(FVL, eg C, C++, assembly language) at the safety application level Principles of specification are implemented at the level of embedded software, firmware, and operating systems; while specifications for the limited application of variable-level languages ​​(LVLs, such as the IEC 61131-3 PLCopen Organization Security Extensions) at the level of security applications are in the IEC standards and ISA. The functional safety of the corresponding standard ISA84 process instrumentation safety system and related technical reports have been detailed and supplemented in this part. Although there is still a long way from recognition and a unified solution, it is sufficient for companies to develop functional safety. designed.

Although functional safety standards have been published, the scope of functional safety research is still deepening and expanding. On the one hand, the research on functional safety of field communication has been partially reflected in the standards of some fieldbus series; on the other hand, it is the influence of electromagnetic environment on functional safety, and these research results have begun to modify the electromagnetics of process control instruments. It is reflected in the compatibility standard.

Many research institutions in China have carried out functional safety research this year. They mainly include: Research on how to propose and determine functional safety requirements for user organizations with high safety requirements, such as petroleum, chemical, and pharmaceutical institutions. They use risk assessment techniques, credibility management methods, HAZOP (Hazard/and/Operability Study, analysis of hazards and reliability) and other methods to determine the target's quantitative requirements for functional safety.

The work of propagating and implementing the two national standards and training functional safety engineers was formulated. At the same time, some institutions carried out functional safety assessments of engineering projects and instrument products.

Some instrument manufacturers started to develop highly reliable functional safety instrument products. In order to allow users to have a better understanding of product certification, individual companies apply for certification from international authoritative organizations.

On the whole, although the research results of China's innovative functional safety are still relatively small, the functional safety activities have started in China and are gradually being developed in depth.

(IV) System maintenance and instrument diagnosis Based on the company's requirements for safety and quality, system maintenance and instrument diagnosis are concerned by users, manufacturers, and researchers. System maintenance and instrument diagnosis are divided into four levels: diagnosis of production processes, diagnosis of production equipment, diagnosis of automated control systems, and diagnosis of field instruments.

The diagnosis of production processes does not, in principle, belong to the category of automation instruments, but the exchange of diagnostic information involves automated instrumentation systems. Foreign instrumentation users have established a user organization MIMOSA (an Operations/and/MaintenanceInformationOpenSystemsAlliance, Operation and Maintenance Information Open Systems Alliance). The organization's mission is to develop and encourage companies to adopt open information standards in OM (Operations/and/Maintenance, Operation and Maintenance) and in Collaborative Asset Life Cycle Management (CALM). It provides a series of related information standards. CCOM (Common Conceptual Object Model) is the basis of all MIMOSA standards, and CRIS (Common Relational Information Schema) provides a means to store information on the operation of enterprise operations. It also provides a metadata reference library and a series of information exchange standards using XML and SQL. The organization also cooperated with OPC and established the OpenPM (Open Operations/and/Maintenance, Open Operation in Maintenance) organization. The basic information standards they developed were multi-industry, MIMOSA provided asset management related information standards, and OPC provided data access to drink transmission standards.

The monitoring and diagnostic instrumentation system for production equipment is a new product that has been introduced to the market in the past two years. Mainly used for the monitoring and diagnosis of some typical production equipment (such as rotating machinery, fluid lines). The detection methods used by these systems include vibration measurement, laser measurement, infrared thermal imaging, ultrasonic scans, and general temperature and pressure measurements. The monitored information is analyzed by expert systems such as statistical analysis, spectrum analysis, pattern recognition, and data mining. The diagnosis of the device. Typical products are Emerson's CSI Machinery Equipment Status Management System.

The diagnosis of the automatic control system is usually a module or a function of the equipment management software in the control system, which is responsible for the control system itself as well as the on-site representation and real-time diagnosis and predictive maintenance. Nowadays, multinational automation instrument companies almost all have their own products, such as Emerson's AMS (Asset Management System) and Siemens' PDM (Process Equipment Management), which are not listed here. The development of diagnostic products for automated control systems has seen a rapid development, with ever-increasing functionality and performance; now the monitoring of production equipment and the diagnostics of automated control systems are often performed on the same platform. In order to improve interoperability at this level, several companies such as Emerson, Siemens and OPC have pledged to cooperate with each other in promoting the unification of interoperability technologies in recent years.

The diagnosis of field instruments is very different from the methods of maintenance and diagnosis mentioned above. First of all, the above method is to collect information through the sensor and achieve diagnosis through analysis of various means. The field instrument itself is small in size, low in power consumption, and has few information resources that can be used for diagnosis. Secondly, the diagnosis results of the field instrument display often rely on the control system software or the hand-held operator. Therefore, the field instrument often has the field instrument and the other end during the diagnosis process. The interaction to supplement the lack of their own resources.

Field instrumentation is more difficult to diagnose. The HART Foundation's HART Diagnostics Guide (Draft) divides maintenance into three levels: Maintenance Required (fault has occurred), Maintenance Required (meter has exceeded maintenance period), Recommended Maintenance Maintenance cycle). The maintenance cycle is determined by the smart meter according to the loss of the meter or a fixed time.

The maintenance and diagnostic research of large-scale equipment in China has a history of many years. There are good results and successful applications in typical equipment such as rotating machinery. Two organizations have gathered our strength in this respect: China Vibration Engineering Society fault diagnosis Professional Committee and Technical Committee on Fault Diagnosis and Safety Technical Process of China Association of Automation. Although there are some studies on the diagnostics of the automation control system itself, the application is less, and the diagnostics of the instrumentation and actuators are weaker. There is a big gap between the maintenance and diagnostic theory research and development practice and the international level. Most domestically produced instruments have gaps in fault diagnosis and predictive maintenance.

In recent years, many foreign papers and patents have been published in terms of maintenance and diagnosis, reflecting that the content of the project is also a hot spot in foreign countries. It is not too late for Chinese companies to catch up.

(5) Wireless Communication The rapid development of industrial wireless communication technology is a remarkable bright spot in the field of automation and instrumentation in the past two years, mainly in the following aspects.

(1) Diversification of technical solutions. There are various schemes based on WPAN (Wireless Personal Area Network), there are schemes based on WLAN (Wireless Local Area Network), and schemes based on wireless public networks (such as GPRS and CDMA). Various programs target certain objects and applications and have advantages in certain areas.

(2) The number of participants increased rapidly. There are schools, research institutes, automated instrumentation companies, as well as some semiconductor device manufacturers and small high-tech companies with specialized technologies.

(3) Established a professional organization. There are newly established special organizations, such as WINA (The Wireless Industrial Networking Alliance, Wireless Industrial Network Alliance), and many established organizations have newly established wireless communication working groups, such as IEEE's multiple working groups, EU's R-Fieldbus project (wireless fieldbus project), ISA's SP100 Working Group, HART

Wireless HART workgroups and wireless workgroups for each fieldbus.

(4) The introduction of a variety of wireless demonstration systems and measurement instrument prototypes has become a hot spot for major automation instrument exhibitions worldwide this year. For example, Honeywell's OneWireless series complying with ISA100.11a and Emerson's SmartWireless complying with WirelessHART. Although these products have already been put into use in some occasions, they are generally limited in quantity; while the two systems are small, but dozens. node. A variety of wireless modules for wireless instrumentation companies to develop wireless products are countless, and companies that provide these modules are often the real holders of wireless technology.

The battle for wireless communication standards has begun. In 2007 when the HART Fund released the WirelessHART standard, Jack Bolick, president of Honeywell Process Systems, issued an open letter that publicized differences between Honeywell and Emerson in wireless communication standards. Since then, various wireless communication standards have been officially submitted to the standardization organizations. In addition to the first two standards for process control objectives, there are standards like ZigBeePro which are not primarily aimed at process control, but have always wanted to penetrate into the field of process control. The ZigBee standard has been updated frequently since its publication in 2003: a new version was announced in 2006 and ZigBee 2007 was announced in 2007. It contains two feature sets ZigBee Pro. The industry is tired of the battle for fieldbuses in the past 10 years. The companies provoked the dispute but did not get obvious benefits. Instead, they gave the small and medium-sized instrument companies an opportunity to the small and medium-sized instrument companies. People want to avoid the recurrence of wireless communication standards. The technical basis for the three kinds of technical cooperation originally existed because the underlying protocols of ISA100.11a, WirelessHART, and ZigBee are all IEEE802.15.4, and the companies that provide chips and communication protocol stacks often provide components of these three technologies at the same time. It is inevitable that these technologies will infiltrate each other. But market competition is not to be transferred by people's will. We may have to face yet another long-standing standard dispute.

It is not too late for China to enter the field of industrial wireless communications. The HART Foundation established the Wireless Working Group in November 2004, and many units in China began to study it before. In the Eleventh Five-Year Plan: Devices, the 863 Program of the Ministry of Science and Technology gave strong support to industrial wireless communications projects. Prior to this, various funds and local science and technology departments of the science and education and education sectors also supported various aspects of the industry.

There are many research units in China based on ZigBee, so it is easier to purchase components and obtain technical support. A number of units have joined the ISA100 Working Group to conduct related research; among them, Chongqing University of Posts and Telecommunications has submitted a number of proposals to the Working Group. There are 27 ISA100.11a committees fully accepted and adopted. There are relatively few units that are truly independent in WirelessHART development in China, because WirelessHART is still continuing to develop itself, and now there is very little technical support provided externally.

From the Miconex exhibition in 2008, the scale and level of our country's current research have not lost the average level of foreign countries and we have exhibited a variety of demonstration systems and products. The most notable achievement in the field of industrial wireless communication in China is that the WIA-PA, a wireless network for industrial process automation researched and developed by the Research Institute of the Shenyang Institute of Automation, Chinese Academy of Sciences, has become a technical specification that can be publicly provided by IEC (IEC/PAS 62601: The 2008 Industrial Communication Network has fieldbus specifications - WIA-PA communication network and communication profile), and WirelessHART has also become an international standard.

(6) Control network The control network technology represented by the site has been gradually promoted in China. Since the field bus has been adopted on a large scale by the Shanghai Secco project, the psychological barriers to the use of field buses in various engineering projects have been basically eliminated. People have less and less asked whether they can use it, and more and more ask how easy it is to use. Due to the large number of large-scale engineering projects in China in recent years, China is in the leading position in terms of both the scale of the project using fieldbus instruments and the quantity adopted. However, although some projects use advanced field bus smart meters, the level of application is not high, mainly due to the incomplete application of information and information services that smart meters can provide.

In the research and development of control networks, China basically tracks international trends. There are Chinese experts in almost every working group of IEC involved in industrial communication networks, and China has proposed its own standard recommendations for most international hot topics. National Standard GB/T20171-2006 EPA system structure and communication specifications for industrial measurement and control systems won the 2008 China Standard Innovation Contribution Award. The EPA series of standards has entered several IEC standards. The EPA series of products run for a long time at several demonstration sites.

The main gap between China and foreign countries in the field of control networks lies in products, both in field bus intelligent field instrumentation and in system products and software.

Internationally, the development of control networks has also entered a steady period of low level, in order to reach people's expectations. There are two technical issues and one non-technical issue here.

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