Abstract This paper introduces an innovative method for controlling a cigarette-making line system using fieldbus technology via Industrial Ethernet (PROFINET). The paper analyzes the rigidity, fixed functions, and high maintenance costs of the original control system, and presents a design scheme for the new system and solutions to control challenges. Through upgrades and improvements, the new cigarette-making line electrical control system is more flexible, meets the requirements of integrated information control, and ultimately improves the efficiency of cigarette production. Keywords: Real -time Industrial Ethernet, Prime line, PLC, PPC 5315 1 Introduction The production process of cigarette manufacturing mainly consists of: cigarette making, cigarette rolling, and packaging. The prime line is the production line that ensures stable cigarette quality. It also has the longest process flow, the most complex procedures, and the most diverse equipment types. The automatic control method of the cigarette making line is divided into process sections such as leaf line, stem line, blending, flavoring and additive addition. Each process section is initially controlled independently via a PLC connected to a fieldbus. Then, the process sections are connected via Ethernet to ultimately complete the corresponding data acquisition and monitoring. This control mode is currently the most widely used in the cigarette industry. 2. Introduction and Problem Analysis of Current Cigarette Making Line Electrical Control Systems 2.1 Cigarette Factory Cigarette Making Line Electrical Control System The cigarette making line electrical control system is the core control system of the cigarette factory's cigarette making production line. A schematic diagram of the system is shown in Figure 1. [IMG=Figure 1 Schematic diagram of the electrical control system for a cigarette manufacturing line]/uploadpic/THESIS/2007/11/2007111609310085546O.jpg[/IMG] Figure 1 Schematic diagram of the electrical control system for a cigarette manufacturing line. The original electrical control system consisted of PLCs, touch screens, and field I/O stations for each process section, with a fieldbus connecting all components. The field layer and the monitoring and management layer were connected via an Ethernet switch. On the production floor, the PLC for each process section was responsible for controlling its own section, sending corresponding control commands according to production process requirements. The fieldbus transmitted commands to the field I/O stations, completing the control of the field actuators, and simultaneously collecting signals from field sensors and transmitting them back to the PLC. The touch screen displayed relevant production parameters, allowing on-site personnel to understand the production line status and receive production operation commands from them. The monitoring and management layer was connected to the field layer via an Ethernet switch. The server collected on-site production information and generated corresponding reports; the monitoring computer monitored the on-site production status in real time and could publish production scheduling plans. 2.2 Problems with the Existing System In the original electronic control system, each process segment was relatively independent, and the procedures were fixed and simple, suitable for mass production of fixed products. However, the current cigarette market is highly competitive, and the development and production of new products require continuous improvement of process technology. At this time, the rigidity of this type of electronic control system is exposed. When a process segment is adjusted, the entire electronic control system of the process segment must be redesigned; adjusting the entire tobacco processing line is equivalent to building a new production line. In addition, the human-machine interface of the on-site touch screen has limited functionality, and when the on-site touch screen malfunctions, the process segment it is responsible for monitoring cannot achieve human-machine interaction; more seriously, when the centralized monitoring computer of the control system shuts down (including normal shutdown and fault shutdown), the entire tobacco processing production line cannot operate normally. The entire electronic control system has a complex structure, is difficult to maintain, and cannot meet the requirements of the current advanced flexible production concept. 3 Design of the New Electronic Control System 3.1 Selection of Control System Automation in cigarette factories has extended from simple automatic control of production workshops and computer use in offices to all aspects of management, control, and on-site management. As Phoenix Contact first proposed the concept of integrated information control in 2004—namely, using Real-Time Ethernet to connect all devices within an enterprise and achieve unimpeded information flow—the industrial Ethernet PROFINET selected here is based on this concept and was jointly launched by INTERBUS CLUB (led by Phoenix Contact) and PROFIBUS USER ORGANISATION (led by Siemens). PROFINET is a holistic solution that uses TCP/IP and IT standards, conforming to real-time automation systems based on industrial Ethernet. PROFINET can achieve seamless integration with fieldbus; it can meet the unified communication needs of all customers, organically combining the real-time performance, ease of use, strong diagnostic capabilities, and economy of fieldbus for transmitting field information with the multi-master, versatility, and ability to transmit large amounts of information at different rates of industrial Ethernet. 3.2 Selection of Field Operator Terminals To better realize field monitoring, the PPC 5315 industrial PC (Phoenix Contact) was selected. This model of industrial PC meets the original field display requirements and provides a universal Windows operating platform, allowing multiple host vendor-developed programs to run simultaneously. Its PCI and ISA universal expansion slots, dual Ethernet ports, and other interfaces make it exceptionally easy to enhance system functionality through external expansion cards. Furthermore, considering the high temperature, humidity, dust, and vibration frequency of industrial environments, this industrial PC features a fanless design, an industrial hard drive, and a shockproof mounting device. It offers good maintainability and robust data protection. 3.3 Selection of Other Control System Components Under normal circumstances, PLCs, field I/O devices, and other components conforming to IEC standards are sufficient. However, due to the adoption of the latest industrial Ethernet PROFINET, new requirements have been placed on the interfaces of related components. PLCs and field I/O substation couplers must have PROFINET interfaces. In addition, switches must support PROFINET functionality to transmit real-time signals. 4. Control System Implementation 4.1 Establishment of the New Control System [IMG=Figure 2 Schematic Diagram of the New Control System]/uploadpic/THESIS/2007/11/20071116093554964242E.jpg[/IMG] Figure 2 Schematic Diagram of the New Control System A redundant fiber optic ring network is constructed using PROFINET switches. Electrical equipment in each process section is no longer physically divided; all are connected to the nearest PROFINET industrial Ethernet network. The logical structure of each process section is completed during configuration and is independent of hardware location. Field operator terminals communicate with all control section PLCs via PROFINET to achieve authorized monitoring of relevant control section equipment. They also connect to the production management layer via PROFINET to directly obtain production data such as production operation plans, batch tasks, and formula parameters, and transmit production information from relevant production sections to the production management layer. The data server also connects to the PROFINET industrial Ethernet network via Ethernet to collect relevant data. Wireless Ethernet switches allow engineers to easily connect their wireless devices to the network for work. 4.2 The new tobacco processing line control process automatically combines tobacco leaf raw materials and tobacco stems according to the requirements of the cigarette leaf group formula; the tobacco leaf pretreatment process heats, rehydrates, loosens, and adds materials to tobacco leaves of various grades, completing the batch leaf mixing task according to the requirements of the leaf group formula; the tobacco leaf processing process outputs the tobacco leaves after mixing and storing them for a specified time from the leaf storage cabinet, and then enters the drying stage after screening, cutting, and humidifying; the tobacco stem pretreatment process rehydrates and softens the tobacco stems, making them suitable for tobacco stem processing; the tobacco stem processing process outputs the processed tobacco stems from the storage cabinet, and then enters the stem cutting machine after steaming, pressing, air cooling, and metal detection; the mixing and flavoring process achieves the proportional blending and uniform flavoring of tobacco leaves, stems, carbon dioxide expanded tobacco, thin sheet tobacco, and recycled tobacco; the tobacco storage and feeding process sends the flavored tobacco leaves stored for more than 8 hours to the corresponding cigarette making unit. 4.3 Key points of control network construction Traditional fieldbus control systems require that electrical devices in the same process section must be directly connected through bus cables. Industrial Ethernet PROFINET does not have this requirement; electrical devices can be connected to the switch nearby, and the logical structure can be built during configuration. Therefore, it is necessary to break away from old thinking and leverage the advantages of information networks to complete network construction. The new industrial Ethernet PROFINET control system brings a problem: a large number of devices are directly connected to the network, resulting in a large number of data packets flooding the network and causing a decrease in communication efficiency. The solution is to use VLANs (Virtual Local Area Networks), that is, to enable the VLAN function in the switch (see the specific product manual), and group electrical devices logically belonging to the same process section into the same VLAN. 5 Conclusion The new electrical control system's PROFINET network integrates powerful functions, from network installation to the implementation of a complete automation solution based on web-based diagnostics; PROFINET's modular structure can be easily expanded and includes other functions; PROFINET provides standardized, manufacturer-independent engineering interfaces, which can easily integrate equipment and components from various manufacturers into a single system. The PPC5135's user-friendly interface not only makes on-site monitoring more convenient, but its communication functions also allow the workshop control room to monitor on-site production in real time. The new control system simplifies the network communication protocol to a single protocol, significantly reducing construction and future maintenance costs. It also lays a solid foundation for the future development of flexible tobacco processing systems. About the author: Zhang Jie (1973-), Bachelor's degree, Electrical Engineer at Baoji Cigarette Factory, mainly engaged in the development and application of industrial control systems. E-mail: [email protected]