Abstract: Continuous production lines for emulsion explosives, expanded explosives, and powdered explosives are advanced explosive production line series successfully developed in recent years through the joint efforts of process, mechanical, and automation researchers. Networking and remote distributed control are achieved through CC-Link fieldbus, reducing system cabling, system failures, and on-site personnel. Supplemented by television and telephone monitoring, production safety and reliability are improved, as well as production efficiency and product quality. Keywords: Continuous production line; Fieldbus; Remote communication; CC-Link; PCC; Configuration software 1 Introduction The application of industrial explosives in industrial production and engineering construction is becoming increasingly widespread. Emulsion explosives, modified powdered explosives, and expanded explosives, as new types of explosives, are showing strong vitality. Due to the unique water resistance of emulsion explosives, the antimony-free nature of modified powdered explosives, and the excellent explosive performance of expanded explosives, the production and use of these explosives are safer, the production environment is pollution-free, and the blasting site is non-toxic, making them increasingly popular among explosive manufacturers and engineering blasting users. Continuous production lines for emulsion explosives, expanded explosives, and modified powdered explosives are advanced explosive production line series developed in recent years through the combined efforts of process, mechanical, and automation researchers. The creation of these continuous production lines has led to breakthroughs in key technologies such as continuous emulsification, continuous sensitization, continuous cooling, continuous modification, continuous mixing, continuous expansion, continuous melting, and continuous dispensing, thus improving the efficiency of explosive production. Using a computer control system to control the entire production line makes explosive production safer, more reliable, simpler, and more convenient, while also improving product quality. Through CC-Link fieldbus and industrial IoT, each production line is networked and remotely controlled and managed, reducing system cabling, system failures, and on-site personnel, thereby improving production safety and reliability, as well as production efficiency and management level. 2. System Composition The control network system networks multiple equipment control stations across the three production lines in the plant area. Dozens of analog quantities such as temperature, pressure, mass, liquid level, and speed, as well as hundreds of start/stop control switches for various electric actuators, can be monitored by the main computer in the central control room according to the process flow. Each field remote control station can independently monitor the production process, working parameters, equipment status, and other operating conditions of its respective production line, and perform fault handling and audible/visual alarms. Automatic or manual control can be performed by field operators. Slave workstations of the control network are set up at the control points of each production line, using Mitsubishi's Q-series or FX2N programmable controllers to collect and monitor analog and digital quantities at each workshop control point. Each slave controller is connected to a Mitsubishi GOT940 touchscreen via its own RS-232 interface, allowing operators to perform local monitoring. The CC-Link communication modules of each slave controller are connected to the CC-Link communication module of the master controller via a CC-Link fieldbus, forming a remote communication control system. The master controller uses a Q-series programmable computer controller, which is connected to the industrial control computer serving as the central monitoring unit via an RS-232C interface, and both are installed in the central control room. (See Figure 1). The central monitoring unit uses an industrial control computer, configured with Kingview 6.5 configuration software from Asia Control Systems, and connected to the company's local area network via TCP/IP protocol to provide production data to the higher-level management. 3. Remote Equipment Station for Continuous Emulsion Explosive Production Line: The continuous emulsion explosive production line consists of continuous processes including melting, emulsification, sensitization, conveying, cooling, and loading, as shown in Figure 2. Melting temperature, cooling temperature, water phase flow rate, oil phase flow rate, and sensitizer flow rate need stable control, employing PID self-tuning closed-loop control. Melting heating temperature control is achieved by transmitting data from a platinum resistance thermometer to the computer, and the computer control program intelligently controls the steam valve's input. Cooling temperature control is achieved by transmitting data from a platinum resistance thermometer to the computer, and the computer intelligently controls the cold water valve's input. Explosive batching flow rate control is achieved by transmitting data from an electromagnetic flow transmitter or mass flow transmitter to the computer. Based on the control requirements, advanced computer control algorithm software is developed to intelligently control the frequency of the variable frequency drive to control the speed of the screw feeder motor. There are also multiple analog detection points for temperature, pressure, and mass, and dozens of switch control points (start/stop control of motors, electric valves, and solenoid valves). A Mitsubishi Q-series programmable computer controller (PCC) and IN, OUT, A/D, D/A, and CC-Link modules are used as the controller to achieve comprehensive control of the production line and communication with the master station. A Mitsubishi GOT-A970 touchscreen is connected to the controller via an RS232 interface and configured using GT Designer, enabling human-machine interaction and monitoring on-site. The Mitsubishi Q-series PCC is a new, high-quality model, primarily utilizing the following functions: ① High-speed processing with an MSP capable of executing optimized sequential control and a high-performance QCPU. The basic instruction processing time of the QCPU is only 34 ns. In large-scale systems, the QCPU can quickly run programs that use indexed structures multiple times; it can simultaneously perform information communication processing and information communication control, ensuring fast and stable control; due to the increase in the number of communications, the system bus speed also increases accordingly, shortening the overall transmission time; it allows interrupt programs to be started from the network or intelligent function modules; it can quickly respond to events that occur asynchronously with program scanning, and compare data received from the network with data from high-speed counters. ② Multi-CPU module systems install two high-performance CPUs on a single base plate. Communication between CPUs can be automatically refreshed, cyclical, or instantaneous. The load can be distributed according to the control cycle to achieve stable and fast control. One CPU is used for fast data processing and control, while another CPU is used for stable drug delivery machine control; the two CPUs can share a single sequential control. ③ IT capabilities and network communication: Q-series PCCs, through the connection of appropriate communication modules or communication boards, can seamlessly communicate with different network types and network layers, such as Ethernet, MELSEC-NET/H, CC-Link, and other companies' fieldbuses like Profibus. Data can be transmitted between any control station connected to the network. ④ Powerful Software Functions: The Q-series programming software, GX Developer, runs on Windows 2000/NT/XP environments. It is suitable for structured function block programming, allowing the creation of sequential control programs through function block calls and releases. Programs written and modified on the host computer can be remotely transmitted to the lower-level PCC, and lower-level network parameters, program passwords, online network connection status monitoring, and online system monitoring can also be remotely set. It also features engineering management, simulation software, and offline debugging functions. 4. Remote Equipment Station for Continuous Production Line of Expanded Explosives The continuous production of expanded explosives consists of four workshops: ammonium nitrate melting, crystallization expansion, oil phase preparation, and loading. Three melting temperatures, two crystallization vacuum levels, and four explosive batching flow rates need stable control. Vacuum control is achieved by a vacuum transmitter detecting and feeding back to the computer, using advanced computer algorithm software to intelligently control the vacuum pump speed. Several analog quantities such as temperature, pressure, mass, and speed need to be detected or controlled, and dozens of digital inputs and outputs need to be controlled according to the process flow sequence. Three melting tanks need to be fed in rotation, and two crystallizers need to crystallize in rotation. The melting, expansion, preparation, and loading workshops use one Mitsubishi FX2N programmable controller and multiple A/D, D/A, temperature, CC-Link, and other modules, as well as one GOT-F940 touchscreen to achieve full-line monitoring and communication. The FX2N is programmed using FX-PCS-UPS/WIN-E software, and the F940 is configured using FX-PCS/DU-WIN-E software. 5. Remote Equipment Station for Continuous Production Line of Modified Powdered Explosives The continuous production of modified powdered explosives consists of a modification workshop, a mixing workshop, and a loading workshop. Analog quantities such as main modification temperature, secondary modification temperature, nitramine flow rate, wood flour flow rate, oil phase flow rate, mixing temperature, and mixing and loading speed need to be stably controlled using PID self-tuning closed-loop regulation to meet control requirements. Several other analog quantities such as temperature, speed, and pressure need to be detected or controlled. Dozens of I/O switches need to be controlled according to the process flow sequence. One Q-series programmable controller and multiple I/O, A/D, D/A, CC-Link communication, and temperature modules are used to control the entire production line and communicate with the master station. An RS232 interface connects to a GOT-A970 touchscreen as the human-machine interface for the production site, as shown in Figure 3. The CC-Link fieldbus uses an open architecture, allowing connection to control equipment from other companies. It employs a polling communication method with frame synchronization. The master station controls the start, stop, and cyclic transmission of data links, periodically communicating data from remote device stations. Dedicated commands can also be used for instantaneous communication between intelligent device stations and the local station. Using the CC-Link fieldbus for remote communication, the longest transmission distance without repeaters is 1200m, at a transmission speed of 156kb/s. High-speed control is also possible, with a maximum transmission speed of 10Mb/s and a transmission distance of 100m. The three explosive production lines are each more than 100m apart, and the central control room is located approximately 200m away from each production line. The management department is located 100m from the central control room and over 200m from the production line. The master station controller's CC-Link communication module, installed in the central control room, communicates with the slave station controllers' CC-Link communication modules on each production line via a CC-Link bus. The transmission distance is set to 600m, with a transmission speed of 625 kb/s. Using dedicated high-performance cables, the transmission distance can reach 900m at a transmission speed of 625 kb/s. Up to 64 remote slave stations can be added to the bus as needed. A maximum of 2048/2048 remote I/O points (RX/RY) and 256/256 remote register points (RWw/RWr) can be linked. Each station can link a maximum of 32/32 remote I/O points (RX/RY) and 4/4 remote register points (RWw/RWr). RX, RY, RWw, and RWr are allocated to the CC-Link module's buffer memory (BFM). Each remote device station can occupy a maximum of 4 stations, connecting to 128/128-point remote I/O and 16/16-point remote registers, meeting the control needs of various production lines. 6.1 Data Link Process Starting the data link: The master station is normal and ready, writes a refresh instruction, and starts the data link using parameters pre-recorded in the E2pROM. Read the data link status of the remote device station and poll the data from the normal slave station. When the data link is normal, the corresponding bit of the link-specific relay indicating the data link status changes to 0N, at which point the slave station can send and receive data. Remote Input: The data from the remote input (RX) and remote register (RWr) of the remote device station is automatically saved to the corresponding input (RX) relay and data register (RWr) in the buffer memory of the master station during each link scan. The PCC uses the FROM instruction to receive the status stored in the buffer memory of the remote input (RX) and remote register (RWr) and transfer it to the corresponding memory relay and memory register. The data is then transmitted to the host computer, where the production line workflow status is displayed through the values ​​of the corresponding (RX) memory relays, and the real-time production line data is displayed through the values ​​of the corresponding (RWr) memory registers. Remote output: The host computer controls the on/off state of the corresponding memory relays of the master station PCC according to the production process, sets the working parameters and writes them into the corresponding memory registers of the master station PCC. The PCC outputs data from these memory relays and registers to the buffer memory output (RY) and register (RWw) using the TO instruction. The data stored in the buffer memory output (RY) and register (RWw) is automatically transmitted to the remote output (RY) and remote register (RWw) of the corresponding remote device station during each link scan. The data link process is shown in Figure 4. 6.2 Setting parameters The parameters that the master station needs to set are: the number of connected modules; the transmission speed; the type, station number, and number of occupied stations for each connected remote station; the number of retries; the number of modules that automatically return; the specified operation when the CPU fails; the specification of reserved stations; and the specifications of invalid stations due to errors. These parameters are pre-recorded in the E[sup]2[/sup]ROM of the master station module, so that the parameters do not need to be written every time the master station module starts. Each slave station also needs to set the corresponding communication parameters (station number, number of occupied stations, transmission speed) and compile the corresponding communication program. 7 Central monitoring station monitoring software The central monitoring station uses Yanxiang industrial control computer, and the monitoring software is developed on the Kingview 6.5 configuration software platform of Asia Control Company. The following functions are designed: (1) Establish connection with the master station controller. The configuration software supports communication methods such as serial port, data acquisition board, DDE, human-machine interface card, network module, etc. The communication between the master station controller program and the configuration software is carried out by connecting the RS-232 interface of the master station controller to the COM1 serial port of the central monitoring PC. The communication driver and configuration program have been made into a complete system, and only the communication parameters of the corresponding I/O devices need to be set. (2) Establish database. The database is the key to the configuration software. The production status of the industrial site should be reflected on the screen in the form of animation. At the same time, the instructions issued by the engineers in front of the computer should be quickly delivered to the production site. All of this is mediated by the real-time database, which is the bridge between the host computer and the slave computer. The database stores the current value of the variables. A total of more than 200 variable points are set for the three production lines. (3) Create multiple functional screens. Object-oriented programming is used to create more than 20 screens for each production line, including on-site simulation screens, fault alarm classification screens, and working parameter settings. The screens to be viewed can be easily accessed by menus or buttons. Define animation connections and use connection expressions to establish a relationship between the graphic objects on the screen and one or more data variables in the database. When the value of the variable changes, the color, size, position, scaling, rotation, value, discrete value, blinking, hidden, and fill percentage of the graphic are changed. When the program runs, the animation effect of the graphic objects is vividly displayed on the screen. (4) Historical trend curves and real-time trend curves. A historical curve screen and a real-time trend curve screen are defined for each production line. A historical trend curve screen can define up to 8 curves. Each curve corresponds to a variable that has been recorded in history. The curves for different time periods can be viewed through various buttons on the screen. A real-time trend curve screen can define up to 4 curves. Each real-time trend curve corresponds to a real-time variable. (5) Real-time data reports and historical data reports. Each production line defines one real-time data report and one historical data report. The report functions can realize various calculations, data conversion, historical data query, statistical analysis, and report printing. (6) Video monitoring. The video control is used to display the on-site images of the production line captured by the camera on the central monitoring computer; the bar chart control is used to create bar charts showing the real-time temperature data of each point. (7) Dynamic data exchange. Dynamic data exchange is used to transfer data from the historical database of the configuration software to Excel to create various complex spreadsheets for production management. (8) Connecting to the industrial network. The configuration software runs on a network based on the TCP/IP network protocol. As a node of the plant-level local area network, it sets the TCP/IP communication protocol, network parameters, and user information tables, and publishes various information on the production line to the network for management personnel to monitor. 8 Conclusion The implementation of the remote distributed control system based on CC-Link fieldbus in explosives manufacturers has greatly improved the reliability and safety of explosives production, improved the technical level, management level and production efficiency of the factory, and improved the performance indicators and quality of products. This control system, in conjunction with the advanced production processes and production line machinery and equipment of emulsion explosives, modified powder explosives and expanded explosives, is being vigorously promoted and used in the explosives industry across the country, and has achieved good social and economic benefits. References: [1] Pan Xinmin, Wang Yanfang. Microcomputer Control Technology [M]. Beijing: Higher Education Press. [2] Tao Yonghua. New PID Control and Its Application [Z]. Beijing: Machinery Industry Press. [3] Asia Control Company. Kingview 6.5 User Manual [Z]. [4] Mitsubishi Electric. CC-Link System Module User Manual [Z]. Original text available for download: Remote Control System Based on CC-Link Fieldbus.pdf