[b]1. Proposal and Requirements of Real-Time Monitoring Systems[/b] In power plants, each production site has its own monitoring and control system, which are generally not interconnected. Therefore, real-time data on the operating status of each production device are scattered across the computers of their respective control systems. Plant leaders cannot monitor the overall production operation status at any time, which is detrimental to the scheduling and management of the entire power plant. In pursuit of higher social and economic benefits, power plants are striving to establish comprehensive Management Information Systems (MIS). These systems must include real-time data from the production site to ensure real-time monitoring of the production process's operational status, thereby enabling optimal decision-making for the entire production, operation, and management process. To obtain the real-time operating status of each production site and piece of equipment in the power plant, a real-time monitoring system must be established within the power plant, acting as an intermediary between the MIS and the field equipment. The system must achieve the following: ① Avoid creating duplicate monitoring stations for units with existing control systems; simply extract real-time information about equipment operation status. ② Avoid creating duplicate monitoring stations for other production stations that have already acquired real-time data; simply extract and configure the data before transmitting it to the MIS. ③ For production stations without data acquisition capabilities, it must be able to collect real-time data from the field. ④ Enable convenient configuration of real-time field data. ⑤ Transmit data accurately and promptly to the MIS. ⑥ The monitoring computer in the MIS should be able to track equipment operation status in real time and provide a clear and standardized display. ⑦ Be easily expandable. The real-time monitoring system sits between the MIS and the field devices. It does not participate in the control of existing field devices but acquires equipment operation status information from these closed or partially closed field device control systems, configures this field information, and transmits it to the MIS. Therefore, the real-time monitoring system must have strong real-time communication capabilities, enabling communication with sensors, ordinary microcomputers, industrial computers, etc., and must ensure the accuracy of data communication, unaffected by strong magnetic or electric fields in the field. **2 System Overall Structure** Considering that the real-time monitoring system needs to acquire real-time data from the production site and transmit necessary updated field operation data upwards, and given that the power plant is a strong electric and magnetic industrial environment with significant interference, a hierarchical structure is adopted. The bottom layer is a fieldbus-based real-time monitoring system, as shown in Figure 1. 2.1 System Network Structure Power plants have extremely stringent production requirements. Any transmission error in the computer network will directly affect the economic and social benefits of the power plant. Therefore, the production and management computer network system must be safe and reliable. For this reason, based on the functions and engineering requirements of the real-time monitoring system, it is designed as an open three-level system: a monitoring and control level, a network data transmission level, and a real-time data post-processing level. The monitoring and control level, also known as the field level, is responsible for data acquisition and preprocessing, unifying communication protocols, and designing and manufacturing communication hardware and software. It connects to various sensors and actuators of the control mechanism and the DAS (Data Acquisition System) part of the DCS system to acquire real-time data from different data sources, forming the basic structure of the fieldbus together. The network data transmission level connects to the monitoring and control level below and the data post-processing level above via various standard communication links. Its main task is to complete real-time data communication, including the installation and debugging of network protocol servers, network system software, and network communication equipment and its driver software. This data network level adopts an open structure, flexibly configured by configuration software to form a free topology, and processes real-time monitoring data according to the requirements of the MIS before sending it to the MIS. The real-time data post-processing level, also known as the integration level, connects the real-time monitoring system and the MIS—two heterogeneous networks—through a router. It links the real-time system data with the monitoring interface and functions developed by the configuration software, realizing the monitoring of real-time data in the field, thereby completing the integration of the real-time monitoring system into the MIS. 2.2 Fieldbus and its main characteristics The basic content of fieldbus is to establish a highly reliable open data communication line in the industrial field to realize data exchange between various sensors and between sensors and monitoring computers. In terms of transmission rate, this data communication line does not pursue the high speed of commercial networks, but focuses on system reliability. In terms of reliability, instead of simply employing multi-machine redundancy, the approach attempts to improve the inherent reliability of the network by modifying the traditional network's communication protocol, adding anti-interference information bits, improving error detection methods, and using a dedicated anti-interference LSI chip hardware communication interface. Of course, this reliability improvement comes at the cost of appropriately reducing the communication rate. Regarding the open architecture, the fieldbus allows various sensors, controllers, and computers from different manufacturers to enter the fieldbus network, greatly facilitating the interchangeability and upgrading of system equipment. Since the real-time requirements for data transmitted over the network in process control are not high, and because a front-end processor is no longer used in this network (its data communication and control functions are embedded in intelligent sensors), while the original system management, background data processing, and system configuration functions are implemented on the management-level computer, system monitoring functions and monitoring points can be flexibly set at any point on the network as needed. System configuration sites can also be arbitrarily set to achieve dynamic configuration functions. The use of intelligent sensors enables system administrators to accurately pinpoint system fault points and predict system failures, raising system reliability to a level unmatched by other systems. 3 Data Acquisition and Data Communication The methods for acquiring data information from three different sources are as follows: (1) Install a network card that supports fieldbus on the engineering station of the DCS system and configure the software. Make the DCS system a station on the fieldbus. Use the development tools of the DCS system to compile data reading and data transmission programs on the operating system of its engineering station, read the data in the DAS and send it out through the fieldbus network. (2) For data from distributed stations, connect it to the fieldbus by configuring the hardware and software that support fieldbus; install configuration software on the distributed stations to realize data acquisition and transmission. (3) For data information that has not yet been acquired, smart sensors can be installed on field devices. Smart sensors have data acquisition and data transmission functions and are directly supported by the fieldbus. Data relay stations are data transfer stations, responsible for receiving data from each data station, and then repackaging and sending the data to the MIS according to the requirements of each monitoring station of the MIS. This can reduce the MIS network occupation time. In order to save network resources as much as possible and reduce unnecessary information transmission, only updated data is transmitted on the network, and no screen is transmitted. Each monitoring station's main screen and curves, tables, bar charts, pie charts, etc., are stored at their respective stations, and the corresponding screens and monitoring functions are dynamically called based on the transmitted data. These screens and monitoring functions are developed by configuration software. [b]4 Real-time Monitoring in MIS[/b] The monitoring and processing of real-time data in MIS involves creating various monitoring screens and implementing related data processing functions. Graphic creation must be simple, flexible, and convenient, while also meeting the requirements for creating complex graphics and conforming to the standardized and regulated drawing requirements of the power system. Data processing, on the other hand, must meet the requirements of real-time performance and openness. Therefore, in order to achieve openness, it is necessary to align with international standards as much as possible and enable the system to support as many industrial control devices as possible. The author believes that an internationally popular software platform should be selected, namely, configuration software, to develop these graphic screens and monitoring function modules to achieve real-time data monitoring and processing. 4.1 Configuration Software General-purpose configuration software for industrial control is a dedicated computer software development platform for industrial control systems that emerged after the complexity of industrial control systems and the development of computer technology to a considerable level. It offers flexible and diverse configuration options, a user-friendly interface, and simple operation. It can also easily implement and complete various monitoring functions of computer integrated systems. Its graphical development tools allow for the rapid design of various screens, and its communication capabilities enable the establishment of dynamic connections between real-time data and corresponding screens. Currently, many international software companies produce general-purpose industrial control configuration software. Compared to software provided by specialized hardware manufacturers, general-purpose configuration software has a better standardized operating platform, can simultaneously support computer hardware and I/O products from various hardware manufacturers, has a standardized graphics library, and boasts high application levels, convenient operation, a user-friendly interface, flexible configuration, and powerful functions. 4.2 Real-time data monitoring Utilizing the communication interface, graphics library, and support for standard databases of the configuration software, MIS can easily complete the following monitoring functions: (1) Real-time monitoring of the dynamic updates of the database in the MIS system server; data refresh can reach the millisecond level, which can meet the real-time data update requirements of the power plant; (2) Transmission of production and operation data required by engineers, shift supervisors, etc., and dynamic generation of corresponding curves, bar charts, pie charts, and reports; (3) Transmission of production and operation data required by plant manager and supervisor stations, and dynamic generation of corresponding curves, bar charts, pie charts, and reports, as well as issuing production instructions, etc. 5 Design of a real-time monitoring system for a power plant The No. 1 and No. 2 units of a power plant adopt the Westinghouse WDPFII control system. This system is not fully open but accounts for 70% of the real-time data, and the automation level of other production stations in the power plant is inconsistent. Therefore, the network protocol of this real-time monitoring system adopts the PROFIBUS protocol in the fieldbus. This protocol was originally a German national industrial standard, and has now developed into a European standard, and is moving towards the FF standard. It has a considerable number of users and supporters in the world. The network stations employ a hybrid storage media operating mode supported by PROFIBUS, meaning master stations operate using a token-based method, and master-slave stations operate in a master-slave method. A token is a special message that transmits bus control (i.e., a token) between master stations in ascending address order. This method ensures that only one master station transmits data at any given time, and any master station can obtain bus control within a specific time slice. This avoids network conflicts and improves the system's reliability. This high reliability and low data transmission speed aligns with the actual production requirements of the power plant. Due to budget constraints, the project was conducted in two phases. The first phase primarily focused on WDPFII data acquisition and transmission. On the WDPFII engineering station (DCH), a data reading program was developed using functions from the Westinghouse development tool library to acquire real-time WDPFII data. This data was then transmitted to the data central station via the fieldbus. After configuration by the FIX configuration software, the real-time data was sent to different stations in the MIS according to the MIS requirements. This process is illustrated in Figure 1. Fig. 2 Real-time monitoring system for a power plant. In the MIS (Manufacturing Logic System), various standard monitoring screens are developed using configuration software according to the actual requirements of each monitoring station, and these screens are associated with their corresponding real-time data (completed through the communication interface of the configuration software). When the real-time data at the production site changes, the relevant curves, bar charts, or pie charts on the monitoring screen change accordingly, activating the corresponding monitoring functions. This real-time monitoring system is completely open; whether it's adding or removing real-time data stations, or expanding or deleting monitoring stations, it's only a local change at that station and won't affect the entire system. 6 Conclusion With the development of MIS, real-time data entering MIS for real-time monitoring is an inevitable trend. Due to historical reasons, the DCS in power plants lacks complete openness, the automation levels of different production stations are inconsistent, and the strong electric and magnetic industrial environment of power plants makes fieldbus the development trend for real-time monitoring systems. Its reliability, openness, and anti-interference capabilities will be of great significance to the structure of industrial site monitoring systems. Configuration software, with its standardized structure, convenient and flexible configuration, powerful drawing functions, and support for various communication hardware, will have a significant impact on the development of industrial monitoring systems. During my research at Zhujiang Power Plant, Shajiao Power Plant, and Zhanjiang Power Plant, the plants' affirmation of this plan and their willingness to cooperate to some extent indicate this trend.