Distributed Control Systems (DCS) are a product of the integration of computer, automatic control, and network communication technologies. Based on the design principles of decentralized control, decentralized hazard, and centralized operation and management, it adopts a multi-level, hierarchical, cooperative, and autonomous structure, adapting to the requirements of modern production and enterprise management. Because DCS integrates the latest fieldbus, embedded software, advanced control, reporting technology, CRT, and network technology, it can comprehensively solve the all-round control of the entire production process, from a single large piece of equipment to a modern factory, providing a basic platform for the factory's full-process information management. Our factory's DCS control system uses the world-class SIEMENS SIMATIC PCS7+CEMAT system. Since the system was debugged and put into normal use nearly two years ago, the DCS system has not only operated very smoothly but has also greatly improved production efficiency. However, we believe that as the company's technical personnel, it is not enough to simply maintain the stability of the DCS system; we must continuously improve and refine it, deeply explore this system, and fully develop and utilize its powerful functions in combination with our factory's actual situation, so that it can be used to the maximum extent possible for the enterprise. Improving the Operational Efficiency of the DCS Control System In normal production, to further optimize operations based on production requirements, a significant number of control points need to be added to the control system. However, during the addition process, it was found that the load rate of the original hardware configuration had reached 96%. Under such conditions, the system not only frequently crashes, but when the load exceeds 90%, it is prone to collapse, posing a significant threat to the operation of field equipment. Through on-site investigation and detailed analysis of the existing situation, and checking a series of CPU operating parameters, the following main problems were found in the system: insufficient hardware capacity, excessive monitoring data, excessive number of address points, need to adjust address configuration parameters, and improper CPU parameter settings. On-site inspection revealed that stations with high CPU loads were those with relatively small CPUs, such as coal mill stations and raw material processing stations. While removing the low-configuration equipment and purchasing higher-level equipment is feasible and relatively simple, it is expensive and requires too much capital investment, making it not the best approach. We do not recommend this method unless absolutely necessary. The high CPU load is mainly due to its relatively low inherent capacity but the large amount of information it is required to process. From this perspective, we sought ways to reduce the amount of information the CPU processes by eliminating unnecessary or less important information. Address points are the sum of absolute and relative addresses. Absolute addresses cannot be further reduced because they are essential data for central control. Relative addresses are intermediate or process variables, and a significant portion of these are optional depending on different requirements. Therefore, we can organize or reduce them based on our existing situation. After resolving each identified problem, the overall operation of the DCS control system improved significantly. In actual control, it fully demonstrated the plant's fully automated control capabilities. Since its commissioning, there have been no malfunctions, ensuring smooth operation for personnel and stable equipment operation. This not only saved the company hundreds of thousands of yuan in hardware investment but also made the operating load of the entire fully automated system more rational and stable, resulting in a zero annual failure rate for the entire DCS system. The expected goals were achieved, yielding significant economic benefits. Using PCS control software to develop information in a real-time management system The main functions of the Siemens PCS7 control system are sequential logic control of electrical equipment, detection and display of process parameters, automatic loop adjustment, and operator management and operation of the controlled production workshop from the central control room. While our company's industrial automatic control system has been operating smoothly, and Hollysys' real-time information management system has been operating normally for six months, it has basically met our company's information management requirements. Under these circumstances, in order to further enhance the transparency of the operation of our company's important production equipment, to further supervise and strengthen the sense of responsibility of personnel in key production positions, and also to provide visiting leaders and managers from other companies with a better understanding of the operational quality of our core equipment, our company leadership requested that a separate information management report be created within the information management system to record and display, under normal feeding conditions: ① current continuous operating time of the kiln, ② last continuous operating time of the kiln, ③ longest continuous operating time of the kiln in history. To realize the function of generating this management information in the information system, I initially designed two schemes. The first solution was to directly utilize the database of the real-time information management system to generate the required time record data for the corresponding reports based on the variable of kiln feed rate. The second solution was to utilize the software of our industrial automatic control system. Leveraging the openness and large-capacity database of our large control system, we could generate the management reports and the required time record management data using a programming language we were familiar with. This data would then be stored in our large database and finally accessed by the real-time information management system. Analysis of Hollysys Information's data software revealed limitations in its ability to use external data for programming. Furthermore, after consulting with experts at Hollysys, they stated that our information management system lacked this functionality. Therefore, our first solution was not feasible and had to be abandoned. We were left with the second solution. Ideally, this task should have been generated by our information management software, but implementing the functionality of information management software within industrial automatic control software proved very challenging. However, to achieve this, we had to further study the characteristics of industrial control software to generate the necessary program. After careful analysis and extensive experimentation and research, we developed and wrote a program in less than ten days. Simultaneously, the important data generated by the program was transmitted to the large database of industrial control for use in our information management system. The software has been running stably since then, with a zero error rate, meeting our company's information management needs and satisfying company leaders. Modification of Central Control Room System Field Station Hardware Configuration The central control room system field stations are the heart of our factory's industrial control system, and the central control room is like our brain. To further enhance the function of this heart, we modified our factory's coal mill field stations and kiln head field stations after careful research. Based on actual production needs, and due to the limitations of the redundancy initially designed by the design institute, in practice, we needed to add a DI module to the field control cabinet in the coal mill's power room to meet the needs of production improvement. At the same time, a DI module also needed to be added to the field station of the central control system at the kiln head. Because the wiring inside the control cabinets of the central control system field stations is very complex, and to meet the needs of production optimization, we had to rewire and recalibrate the front and rear modules and wiring of the cabinets. To achieve this, we mainly adopted the following steps: 1. Check the current hardware configuration and wiring status inside the control cabinets of each central control field station. 2. Locate the locations where hardware needs to be added. 3. Wiring the hardware modules and installing them onto the selected ET200M motherboard. 4. Connecting and calibrating the wiring to the rear terminals of the cabinet. 5. Adding and configuring hardware at each station on the engineering station. 6. Defining the address and symbol of each global variable, editing and downloading it to each central control field station. Currently, all field stations are operating normally, the newly added modules are operating normally, and the controlled equipment has not experienced any malfunctions. Making full use of existing resources to promptly achieve communication between the two DCS control systems . In late October, the installation of electrical equipment at our company's waste heat power plant was nearing completion. The communication interface between the waste heat power plant's DCS control system and the cement clinker DCS control system became a problem that needed to be solved promptly. At the same time, the cement clinker production line entered a 7-day maintenance period. To take advantage of this opportunity, we planned to achieve communication between the two systems during this period. On the 26th, we, along with relevant leaders from the power plant and personnel from the installation company, conducted a thorough analysis and discussion regarding the integration of the two systems. Based on the requirements of the cement clinker production line and the needs of the waste heat power plant production line, we determined that the two electric valves at the kiln head—the boiler inlet valve controlled by the clinker production line and the outlet valve controlled by the waste heat power plant production line—and the boiler inlet valve at the kiln tail controlled by the clinker production line and the outlet valve controlled by the waste heat power plant, with the large inclined valve controlled by the clinker production line, would all be powered by the waste heat power plant. The opening degree of each valve would be displayed accurately and promptly at the waste heat power plant. To achieve these functions, we carefully considered and decided to use a one-input, two-output communication module. However, upon checking our warehouse, we discovered we did not have this type of communication module. Purchasing it would require a significant amount of capital and a long waiting time. To ensure communication during clinker production line maintenance and prevent disruption to normal production due to the integration of the two systems, we decided to consider other solutions. Finally, the research decided to use existing equipment and develop new software within the DCS control system of the clinker production line to achieve communication between these devices. To achieve this, we first conducted an in-depth study of the program for our company's clinker production line's automatic control system. Then, based on the existing functions of the DCS control system, we developed the program. After the program was developed, for safety reasons, we first developed a software simulation test within the existing software. After a series of modifications, the simulation software successfully achieved communication. Next, we installed the field equipment and set up the hardware, downloaded the program to the field central controller, and connected the corresponding field equipment and the communication cables between the two systems to establish communication. The field control equipment operated normally, and the two systems could communicate accurately and promptly. The operation status of each valve in the clinker production line was accurately displayed on the control panel in the control room of the waste heat power plant's central control system. In this way, communication between the clinker production control and waste heat power plant control systems was achieved, meeting the requirements of both production lines. Despite lacking all the necessary hardware, we successfully established communication between the waste heat power plant's DCS control system and the cement clinker DCS control system using existing spare parts and software resources. This not only prepared the waste heat power plant for operation but also reduced the number of shutdowns in the clinker production line due to the integration of waste heat power generation. Furthermore, it saved the company considerable funds on purchasing a dual-input, dual-output module. Siemens and Rosmont instruments were used simultaneously on the same bus . Our company's first 5000t/d new dry-process clinker production line utilized Siemens and Rosmont fieldbus instruments at its main control points. The combined application of these two products, with their different core technologies, on the same bus yielded excellent results. Fieldbus technology integrates digital computing and communication capabilities into the internal devices of traditional, low-level field control equipment and measuring instruments. It connects to standard bus interfaces via simple twisted-pair cables, enabling the connection of various devices and instruments directly deployed in the production field, such as valve positioners, level gauges, pressure/differential/temperature transmitters, analyzers, flow meters, and I/O modules, into a production process monitoring and control network system. This system then connects to higher-level high-speed communication lines to form a distributed control system operating on the publicly compliant communication protocol (PROFIBUS DP bus communication protocol). This facilitates data acquisition, transmission, control, and management between multiple microcomputer-based measurement and control devices and between instruments and remote controls, achieving various automation control requirements. PROFIBUS conforms to the German national standard DIN19245 and the European standard EN50170. Our company uses Rosemount pressure and temperature instruments manufactured in Singapore using the PROFIBUS PA bus standard. The pressure instruments are model 3051, and the temperature instruments are model 3244. We also used Siemens temperature and pressure instruments as spare parts. During production, due to material leakage, our company is currently using five Siemens bus instruments: three temperature instruments and two pressure instruments. The pressure instruments are SITRANS P DSIII, and the temperature instruments are SITRANS T3K PA. To determine if the Rootsmont instruments could be used on this production line, we first tested them on the fieldbus of another cement production company, and the results were good. This initially proved that this type of bus instrument can communicate using the PROFIBUS communication protocol. Since the Rootsmont bus instruments are manufactured according to the PROFIBUS PA communication standard, we can infer that this type of instrument should be able to be configured and communicate with the fieldbus instruments in the PCS7 process control system. In other words, the Siemens process control system should also support the Rootsmont fieldbus instruments. To verify this inference, we had Siemens experts conduct specific experiments at the Siemens headquarters laboratory in Beijing, and the conclusion was affirmative. Due to limitations at the time, the PCS7 control system could only control Rosemount instruments. However, the specific address and parameter settings were beyond the scope of domestic implementation, and the parameter settings varied between instruments from different companies. We had to develop our own system. Our company's DCS system used Siemens PCS7 control software for the host computer, and Siemens PDM software and GSD files for programming and configuring the bus instruments. After configuring the bus instruments according to the experimental method, the field instruments could not be found on the host computer. Analysis revealed that ABB and Siemens PA instruments all had a default bus address of 126 bits at the factory, and our Rosemount PA instruments also had a default address of 126 bits. Since all field instruments had the same address setting, the system could not recognize each bus instrument. Our solution involves using a PC and a CP5511 card to individually configure the addresses of each Rosemount PA instrument to be unique before connecting the DP/PA bus of the DCS field cabinet to the bus instruments. This ensures that each instrument on the same bus has a unique address. Then, we connect to the system and use GSD files to configure the detailed parameters of each instrument. The hardware configuration method is the same as for Rosemount instruments, so it will not be repeated here. The address setting method is as follows: Since our company uses a Siemens instrument that is connected after it is running normally, after the hardware configuration, only one instrument in the field has an address of 126. Therefore, this instrument can be found in the host computer. After finding the instrument, we can change the address according to our needs. The symbol table editing is as follows: On the configured hardware, click on the instrument diagram for which you want to set variables. The symbol setting table for that instrument will be displayed at the bottom of the screen. Right-click on the first row of the symbol table, select the symbol editing option in the pop-up dialog box, and the symbol editing screen will be displayed. The first row of this table is the position of the symbol to be defined. Here, you can define the variable according to your needs. After the defined symbols are compiled and saved, they can be edited and used in the host computer. These two types of bus instruments have been running on the same PA line in our factory for over a year, and both instruments have been operating stably without any malfunctions. From our company's operational experience, we can see how powerful the openness and compatibility of Siemens' process control system are. As long as the equipment conforms to the communication standards, it can be used reliably in the Siemens PCS7 control system. This fully demonstrates the superior functionality of the PCS7 control system. This application research resolved the compatibility conflict between the Siemens PCS7 control system and the Rosemount fieldbus PA instruments, enabling the entire control system to achieve production operation on time and smoothly. More than two years of production application have proven that all Rosemount and Siemens fieldbus temperature and pressure instruments in our factory are operating stably, providing reliable data, and performing well. Coal Mill Hydraulic Station Converted to DCS Control The control of the hydraulic station of the coal mill on our factory's first clinker production line was initially designed manually by the Hefei Design Institute. In normal production, manual control can generally meet production requirements. However, a major drawback of coal mills is that during normal production, a dedicated worker must be present at the hydraulic station to raise and lower the rollers according to actual production needs, resulting in a low level of automation. More importantly, when abnormal conditions occur within the coal mill, such as abnormal vibration, the operator must immediately lift the rollers to prevent further damage. However, due to the inherent limitations of human intervention, it's impossible for workers to be constantly on-site to adjust the hydraulic system. Therefore, in such situations, excessive vibration can cause the mill to trip. Since a mill is a large piece of equipment, repeated trips due to excessive vibration can cause significant damage to the entire mill. To overcome these shortcomings, our company's leadership decided to add an automatic hydraulic control system to the coal mill's hydraulic station. This system is connected to the manual control system, serving as a backup for each other. The main equipment in the automatic hydraulic station control system includes a main oil station motor, a main valve, valves 1 and 2, a directional valve, and an unloading valve. In the hydraulic circuit control, the functions we need to achieve are: 1. Adjusting the grinding roller pressure according to production needs. Through research, we found that, given the limitations of the control system, the only way to achieve pressure adjustment is by adjusting the proportional valve. 2. Pre-adjustment: First, lower the grinding roller onto the grinding disc and start the main motor of the hydraulic station. When the pressure reaches the set value, stop the main motor. 3. Roller lowering: All equipment is off, and the grinding roller falls onto the grinding disc by its own weight. 4. Roller lifting: The lubrication pump runs, and the reversing valve and unloading valve are energized. When the grinding roller reaches the upper limit, the pump stops running, and the reversing valve and unloading valve are de-energized. Simultaneously, the pressure must be set to an appropriate value during roller lifting. All of the above functions have been implemented in our large central control system. To achieve these functions, I developed several control schemes for our control system. Through numerous experiments and continuous modifications, we finally achieved complete automatic control of the coal mill hydraulic station, improving the system's automation level. The successful implementation of this automatic control system not only improved the automation level of the coal mill control system and reduced the labor intensity of the work, but also played a significant role in protecting our company's coal mill equipment. Since its commissioning, the system has operated stably. Since the SIMATIC PCS7+CEMAT system was put into operation on the clinker production line, we overcame the difficulties brought about by the lack of readily available technical experience during project implementation. Through continuous practice and exploration, we improved and optimized the design, explored the system's functions in depth, and attempted to interface with other domestic DCS systems. Currently, the system is operating well, with accurate and reliable control, simple operation, and convenient maintenance. It achieves the goals of energy saving, efficiency improvement, and environmental protection, creating considerable economic and social benefits for the company; at the same time, it has certain reference value for other cement companies in the same industry.