I. Introduction In today's highly developed information technology era, the petrochemical industry, as a traditional industry, remains a crucial pillar industry for a nation's economic development. Over the decades, petrochemical automation technology has developed alongside advancements in processes and equipment. From initial simple manual operations to continuous processes and increasingly demanding loads, the requirements for production stability, control, and automation levels have risen significantly. Instrumentation has become more widespread, evolving from simple closed-loop control to comprehensive automation of unit devices. Control tools have also evolved from pneumatic and electric unit instrument combinations to the widespread application of DCS (Distributed Control Systems). Control levels have progressed from simple single-parameter control loops to complex multi-variable control loops, with advanced control systems and optimized control systems finding successful applications in various settings. With the further expansion of industrial scale and the successful development of rapid-response, critical-stability, and energy-balanced processes, even higher demands are placed on automation. Furthermore, fierce market competition has set new goals and requirements for automation. Simultaneously, information technology has injected new vitality into the development of petrochemical automation technology. II. The Application of Fieldbus Will Be Gradually Promoted Fieldbus is a network interconnection technology used in production sites to achieve fully digital, serial, bidirectional, and multi-variable digital communication between field instruments (including transmitters, actuators, recorders, single-loop controllers, programmable logic controllers, etc.) and between field instruments and control equipment. Its emergence has had a significant impact on the field of industrial control technology. Although the international fieldbus standard IEC 61158 includes eight types of fieldbuses (now increased to ten) such as FF, Profibus, ControlNet, WorldFIP, and P-NET, it has not achieved its initial goal of "establishing a single fieldbus," and has also signaled the coexistence of multiple fieldbuses. However, compared with existing DCS and PLC systems, Fieldbus Control Systems (FCS) remain the development trend of basic automation systems in the petrochemical industry due to their characteristics such as fully digital multi-point communication, controllable field device status, openness, interoperability, and the ability to achieve distributed control. However, in the near future, the promotion and application of FCS will exhibit the following characteristics: (1) FCS will coexist with DCS: Since its emergence in the 1970s, DCS has gone through several stages of development, maturity and large-scale application, and has adopted a large number of advanced and mature technologies. DCS technology is mature, reliable, rich in software and complete in function, and has gained the trust of users, and has become the main means of industrial production process control. FCS is still in the development stage, the technology itself is not yet mature (such as the network redundancy problem has not yet been well solved), the reliability has not been fully verified, and the function is not as complete as DCS. Therefore, although users pay attention to the development of FCS, they still have doubts and mostly hold a cautious wait-and-see attitude. In addition, for situations where the system scale is small, the controlled objects are relatively concentrated, and there is no requirement for intelligent diagnosis and management of extended equipment, the advantages of fieldbus cannot be fully reflected, and large-scale replacement of existing DCS equipment will inevitably cause huge waste. Field intelligent device management based on fieldbus has also been hyped as a hot selling point of fieldbus, but after careful analysis of the equipment management products provided by major companies in the world, there is nothing new. For example, equipment fault diagnosis is a complex science. It requires the integration of knowledge from multiple disciplines such as mechanics, electronics, and computers to establish equipment fault models and collect a large amount of equipment operating status information for detailed analysis in order to make accurate and meaningful judgments and provide real guidance for equipment maintenance. Unfortunately, most current equipment management software products do not achieve this. In short, DCS has developed to a very mature and practical level and is still the mainstream of current industrial automation system application and selection. It will not disappear from the historical stage immediately with the emergence and development of FCS. On the contrary, DCS will coexist with FCS for a considerable period of time in the future. (2) Combining fieldbus with DCS: Integrating fieldbus technology into existing control systems, connecting fieldbus smart instruments to DCS, and using the rich and mature control functions and software and hardware products of DCS to promote the application of fieldbus. Generally, there are three main approaches to integrating fieldbus with traditional control systems: First, integration at the I/O level of DCS and PLC, where fieldbus devices are integrated as I/O cards within the DCS and PLC; second, integration on the DCS and PLC network, where fieldbus devices are integrated into the DCS and PLC via a gateway for unified configuration, monitoring, and management; and third, information integration between independent FCS and DCS/PLC, where the FCS and DCS/PLC operate independently, with information mapping and communication between them achieved through a gateway. Given the continued widespread use of traditional control systems, these methods not only leverage the mature technology and experience of DCS and PLC but also capitalize on the advantages of fieldbus. Furthermore, based on the widespread application of fieldbus, integrated management and control functions can be gradually improved. Utilizing the all-digital communication capabilities of fieldbus, a large amount of non-control information provided by field intelligent devices can be collected, establishing a field intelligent device database. This allows for the establishment and improvement of remote management functions such as remote status monitoring, fault diagnosis, preventative maintenance, and online calibration of field intelligent devices, achieving integrated management and control of field equipment. (3) Multi-bus integration and "automation islands" The international standard IEC61158 for fieldbuses has not been able to unify all fieldbuses. In addition to market interests, different fieldbuses are developed for specific application areas and have their own technical characteristics. Therefore, no single bus can replace all other fieldbuses. For example, FF and HART have certain characteristics in the processing of continuous signals, while PROFIBUS and INTERBUS have certain advantages in the processing of switch signals. Therefore, in the future, regardless of the form of basic automation control system, it will have the ability to interconnect and integrate multiple fieldbuses. Regardless of the form of control system adopted, it is necessary to solve the problem of "automation islands" between different fieldbuses and different types of control systems, and connect DCS, PLC and other intelligent devices from various manufacturers to a unified database platform for unified scheduling and sharing. (4) Ethernet fieldbus With the development and popularization of Internet technology, Ethernet has the characteristics of wide application, low cost, high communication speed, rich software and hardware resources and great potential for sustainable development. It is gradually penetrating from the commercial communication field to the control field and is widely used in the communication between control and management layer devices in industrial enterprises. In response, international multinational corporations have launched Ethernet-based fieldbus technologies, such as EPA from Zhejiang University Control System, ProfiNet I/O from Siemens, and EtherCAT and PowerLink from the European Open Networking Consortium (IAONA). These real-time Ethernet protocols have been included in the international standard IEC 61784-2 for real-time Ethernet applications, which is currently being drafted by the IEC. Because real-time Ethernet fieldbuses not only integrate the characteristics of existing fieldbuses but also combine with mature technologies in the information field, they will be widely used in the field of petrochemical automation control. III. The Integration of Information Technology and Automation Technology – Industrial IT With the continuous maturation of the Internet, it has connected the previously independent fields of computers and communications, not only bringing stand-alone computers into the Internet era but also rapidly promoting the development of the computer and communications industries. On the other hand, with the widespread application of information technology and microelectronics in automated instruments and control systems, and the integrated development of industrial control networks and information management networks, the digital data acquisition, regulation and control, monitoring and configuration design, equipment maintenance, production management, and business decision-making processes in enterprise production will be unified into a complete integrated automated information system through an integrated network communication platform. This will achieve the digitalization of field equipment, the intelligentization of production process control, the informatization of enterprise management, and the networking of consulting services. Experts predict that in this integrated automated control information system, traditional control information will decrease from 85% to 40%, while business management information will rise to 60%. Therefore, the industrial control field has acquired the characteristics of contemporary IT technology and industry, namely the so-called Industrial IT. Among them, "intelligent" industrial automation instruments and industrial control networks constitute the technological foundation and hardware platform of Industrial IT. Building upon this foundation, by employing real-time database technology, soft measurement technology, data fusion and processing technology, advanced control and process optimization technology, ERP technology, and IT technologies such as network technology, communication technology, and information processing technology, remote monitoring, fault diagnosis, and maintenance of industrial production processes can be achieved, realizing integrated management and control across the entire industrial plant. In fact, since the invention of the computer, automation technology has been closely integrated with information technology. The development of information technology has provided automation technology with increasingly more means and more convenient tools, transforming many advanced techniques in automation technology (such as various complex PID algorithms and advanced algorithms such as uniform control, decoupling control, and fuzzy control) into relatively easy-to-implement software code. It is precisely because of IT technology that many theoretical concepts in automation technology have become reality. Currently, with the booming development of IT technology, how to better, faster, and more extensively apply IT technology to automation products is a common topic faced by all automation product suppliers. The ability to apply IT technology to automation technology as much as possible is gradually becoming a crucial factor determining a company's competitiveness. First, how to better apply IT technology, and second, how to generate benefits through optimization, combined with specific processes and equipment, to tap the potential of equipment and processes, promote increased output, reduced consumption, and make the production process safer. In short, it is: "to seek benefits from control and optimization". In addition, how to turn the "automation islands" in the enterprise into a unified platform, realize "process visualization", expand information sharing, improve information utilization, improve the level and effectiveness of enterprise decision-making, and realize integrated management and control, "to seek benefits from management and information systems", is also a major issue. Generally speaking, industrial "IT" has the following characteristics: digital intelligence of field instruments, digitalization of production processes, digitalization of design, digitalization and informatization of management. Specifically, it is manifested as: (1) a new type of industrial automation network system technology based on modern computers, networks, communication and modern control technology, which serves the process industry and manufacturing industry. On the basis of further improving the information acquisition function, it strengthens the processing of information, especially the network transmission technology of industrial production process measurement and control information is more open and has developed rapidly. (2) traditional automation instruments are moving towards digitalization and intelligence, with open network communication interfaces, and have become a node of networked control system. Distributed industrial control networks will become the dominant technology of future control systems. (3) Using industrial control networks such as fieldbus and industrial Ethernet as platforms, and utilizing the software and hardware resources (such as functional modules) of field devices, fully distributed control can be achieved. At the same time, remote access, monitoring, calibration, diagnosis, maintenance and other management functions can be realized for field instruments. (4) The control system and information system can achieve smooth connection and multi-network integration. Industrial Ethernet technology will be more widely promoted in the control field. Real-time control information can be shared and online detected, controlled and managed through Intranet/Internet. (5) Industrial control system software and various application software development and system integration technology will become core technologies, replacing system hardware as a carrier of high added value. Through advanced control and optimization software, advanced intelligent control such as predictive control, fuzzy control, neural network control, and expert system control can be realized, as well as optimized management of production processes such as data correction, process simulation, quality monitoring, production planning and scheduling, fault diagnosis, and safety management. (6) Enterprises use Enterprise Resource Planning (ERP) and Supply Chain Management (SCL) software as platforms to achieve integrated management of bill of materials, process routes, inventory management, production planning, material requirements planning, capacity requirements planning, cost management, financial management, sales management, product data management, quality management, equipment maintenance management, laboratory management, transportation management, formula management, human resource management, strategic management, customer service management, and development and research management. (7) Dedicated IC chips, communication modules for various industrial control networks, bridges, repeaters, gateways, remote I/O nodes, and functional modules have become key products in the new generation of distributed network control systems and are developing in sync with network information technology. IV. Enterprise integrated automation will become an effective means for enterprises to improve their core competitiveness. After 50 years of development, China's petroleum and chemical automation has made great progress in automation through technology introduction, digestion and absorption, and continuous innovation. With the rapid development of China's economic construction, China's petroleum and chemical industry has encountered unprecedented development opportunities, but at the same time, it is also facing increasingly severe challenges. Compared with developed countries, my country's petrochemical industry generally suffers from problems such as high energy consumption, poor product quality, outdated production processes, low levels of automation, low management levels, low information integration, and weak overall competitiveness. Enterprise integrated automation systems (CIMS) combine advanced process equipment technology, modern management technology, and information technology, represented by advanced control and optimization technologies, to control and manage the enterprise's production processes as a whole, providing comprehensive solutions to achieve optimized operation, control, and management, thus becoming a core high technology for improving enterprise competitiveness. Large foreign process enterprises, especially petrochemical companies, attach great importance to the application of information integration technology, and have devoted considerable enthusiasm and effort to building plant-level, company-level, and even super-company-level information integration systems. By 1995, more than 100 refining and chemical companies in the United States, Japan, and Western Europe were implementing CIMS programs, promoting the application of integrated automation technology in actual production in the process industry. For example, companies such as Mitsui Petrochemicals Co., Ltd. of Japan, Desoc Corporation of the United States, and Gore-McMoRan have successively established integrated automation systems. Generally speaking, process industry enterprises' needs for integrated automation technology mainly focus on four aspects. (1) Safety: This means that a highly reliable control system, detection and execution mechanism is needed to ensure the operation of equipment and devices, and then to carry out fault diagnosis and health maintenance of key devices. (2) Low cost: Reduce energy consumption and raw material consumption through advanced processes and process parameters, and improve product qualification rate and conversion rate through advanced modeling technology, control technology and real-time optimization technology. (3) High efficiency: Improve equipment utilization and labor productivity through advanced planning, scheduling and production scheduling technology and process simulation technology. (4) Improve competitiveness: Promote the value-added of enterprises through the comprehensive integration of data and information, such as advanced management technology (including ERP, CRM, SCM, etc.), e-commerce, value chain analysis technology, etc., and ultimately improve the comprehensive competitiveness of enterprises. According to the development trend of integrated automation technology at home and abroad and the current status of network technology, the overall structure of integrated automation technology in the process industry can be divided into three layers, as shown in Figure 1. [align=center] Figure 1 Overall structure of integrated automation technology in the process industry[/align] (1) Basic automation layer represented by PCS (process control system). The main contents include advanced control software, soft measurement technology, real-time database technology, reliability technology, data fusion and data processing technology, distributed control system (DCS), field control system (FCS), multi-bus networked control system, field control equipment based on high-speed Ethernet and wireless technology, sensor technology, special actuators, etc. (2). Production process operation optimization layer represented by MES (Manufacturing Execution System). The main contents include advanced modeling and process simulation technology (AMT), advanced planning and scheduling technology (APS), real-time optimization technology (RTO), fault diagnosis and health maintenance technology, data mining and data correction technology, dynamic quality control and management technology, dynamic cost control and management technology, etc. (3) Enterprise production and operation optimization layer represented by ERP (Enterprise Resource Management). The main contents include enterprise resource management (ERP), supply chain management (SCM), customer relationship management (CRM), product quality data management (PqDM), data warehouse technology, equipment resource management, enterprise e-commerce platform, etc. By studying the Manufacturing Execution System (MES) and related technologies, online cost prediction, control and feedback correction can be achieved to form a production cost control center and ensure the optimized operation of the production process; the entire production process can be optimized and uniformly commanded to form a production command center and ensure the optimized control of the production process; the production process can be quality tracked and safety monitored to form a quality management system and equipment health assurance system and ensure the optimized management of the production process. The key technologies that need to be addressed in enterprise integrated automation are: (1) Information integration, mining and value-added information integration is the core of integrated automation, while the database management system is the foundation of information integration. Due to the characteristics of the process industry, a large amount of real-time massive data reflecting the status of the production process needs to be processed, managed and effectively applied. Therefore, the real-time database management system is the basis for using real-time data to supervise and control the production process and to analyze and evaluate the production status. Therefore, the information integration environment of the process industry needs to set up a relational database and a real-time database system at the same time as the information distribution center of the entire system. These two databases can operate independently or work together to process various information from the whole plant in a timely, parallel or cross-processing manner, and truly achieve information integration and sharing. The purpose of information mining and value-added services is to make full and effective use of information. (2) Scientific decision support. Production and operation decision-making is an important part of enterprise production and operation activities. However, the traditional production management model is still based on experience-based decision-making and has a large degree of arbitrariness, while scientific decision support is the key to the success or failure of enterprise operation. Cost-benefit analysis refers to the process of analyzing and evaluating the production and operation activities of an enterprise using financial analysis methods to obtain the comprehensive economic indicators of the entire enterprise. In the comprehensive automation of oil refining enterprises, cost-benefit analysis is an important link in the production management of oil refining enterprises and a necessary step in the production and operation decision-making of oil refining enterprises. Cost-benefit analysis aims to maximize the enterprise's profits. By conducting cost-benefit analysis on the production and operation of an enterprise and, on this basis, conducting profit and loss analysis on the production plan, the enterprise leaders are provided with economic indicators of the actual production and operation process and production plan to improve the enterprise's decision-making level and strengthen the enterprise's competitiveness in the market. In order to achieve the profit target set by the company in advance, it is necessary to coordinate the work of various departments of the enterprise, namely, crude oil procurement, production plan formulation, production scheduling and product sales. Since crude oil is the main raw material for refinery production, crude oil cost accounts for 80-90% of the total product cost. Therefore, in order to achieve the profit target, it is necessary to control the crude oil cost first, that is, control the purchase price of crude oil. Break-even analysis refers to using financial analysis methods and mathematical tools to analyze the production and operation plan or program, and to obtain the highest crude oil purchase price (profit point) to achieve the profit target and the highest crude oil purchase price (break-even point) to ensure no loss operation (profit of 0). Break-even analysis has important reference value for crude oil procurement, cost control and economic efficiency improvement. It is an important link in formulating reasonable production plans. It is of great significance for controlling production costs, expanding profits and thus ensuring the realization of profit targets and guiding the production and operation of the whole enterprise. (3) Conduct process simulation and establish process model to realize process optimization operation. Conducting process simulation, establishing process model and realizing process optimization operation is another key technology for the comprehensive automation of process industry. The scientific production planning/scheduling is the key to achieving a certain degree of production flexibility in the refining production process. It is a research topic that is widely valued by the academic and industrial communities. Due to the highly complex nature of oil refining production, it is essential to closely integrate production process mechanism modeling with systems engineering theory to find solutions to this problem. Practical results show that establishing a computer-aided production planning/scheduling system based on full-process simulation, combined with the application of linear programming, nonlinear programming, or dynamic programming, is an effective way to achieve optimized production scheduling/dispatching. Process operation optimization is another key aspect of adapting the oil refining industry to changes in market demand for raw materials and products, making production flexible. The primary technical challenge is establishing a steady-state mathematical model of the process. Due to the complexity of the technology, the different mechanisms of different units, and the unclear mechanisms of some complex reaction processes, modeling involves both process mechanism and information processing technologies, making it interdisciplinary and extremely difficult to establish models for industrial applications. Furthermore, soft sensing technology, new equipment process fault diagnosis technologies, production process safety protection technologies, and data adjustment technologies for processing real-time measurement data are all pressing problems and research hotspots in the field of automation. V. Conclusion Applying fieldbus technology and information technology to the petrochemical industry, and developing comprehensive automation solutions and integration technologies, can improve product quality, increase product output, reduce production costs, achieve significant economic and social benefits, and enhance the competitiveness of enterprises. This represents the future trend of automation technology development and application in the petrochemical industry.