Abstract : This article briefly describes the hardware composition, network structure, software control functions, and system characteristics of the computer control system for the Sendzimir 20-roll mill. After the system was put into operation, the output was greatly increased, resulting in good economic benefits. Keywords : mill; computer; control system The Sendzimir 20-roll cold rolling mill was manufactured by DMS of France. It is approximately 27 meters long and the rolling line height is 1.1 meters. The main equipment of the rolling mill consists of a 20-roll Sendzimir mill, three coil moving trolleys, an uncoiler, a CPU centering device, a five-roll straightener, left and right coilers, five sets of paper rollers, two sets of oil wipers, two sets of thickness gauges, a shape gauge, two sets of transverse disc shears, a roll changing trolley, an underground oil depot, a hydraulic lubrication system, a rolling oil filtration system, an oil depot smoke exhaust system, and a fire protection system. The 20-roll mill's computer system uses one HPC control computer, eight workstations, and two servers, forming a three-level Ethernet network with the drive system. This network is used to control the AC main drive system (uncoiler, left and right coilers, main mill), motor control center, hydraulic solenoid valves, rolling sequence control, hydraulic system, filtration and distribution system, lubrication system, and other components. A simplified process diagram is shown in Figure 1. [align=center]Figure 1 Process Diagram of the 20-roll Mill[/align] II. Hardware Composition The 20-roll mill computer system uses one HPC computer control cabinet to control the AC main drive system of the uncoiling, coiling, and main mill, as well as the motor control center, hydraulic solenoid valves, rolling sequence control, hydraulic, filtering, and lubrication sequence control sections. The HPC rack configuration is shown in Figure 2. [align=center]Figure 2 HPC Rack Configuration Diagram[/align] The HPC computer control cabinet hardware consists of a CPU card, an analog input module ICV 150, a digital input/output module ICV196, a pulse counter input module DZ232, an analog output module MI16IAO, an HE700-GEN200 (N80 network interface), a ProfiBUS bus conversion module SST5136, an OptoBUS bus conversion module VLI041, and the rack. ■ CPU Card Model: VMIVME-7698-345 Celeron Processor, 256M DRAM Memory, 64-bit AGP Graphics Accelerated Graphics Card ■ Analog Input Module ICV 150: 32 differential channels or 64 single-channel inputs, ±10V ■ Digital Input/Output Module ICV196: Provides 96 digital inputs/outputs (12 groups of 8 channels), maximum protection 70V, maximum current 300 mA ■ Pulse Counter Input Module DZ232: Allows the following types of measurements: 32-bit position measurement (pulse counting); 24-bit period measurement (time counting), the period is determined by the time interval between two edge pulses of the rotation sensor. The time reference is determined by a timer or a multiplexed synchronization signal of the VME bus. ■ Analog Output Module MI16IAO: 12-bit resolution, maximum current 4-20 mA ■ HE700-GEN200 (N80 Network Interface): HE700-GEN200 is a single-slot VME module. The network device supports communication terminals, serial port 1, serial port 2, shielded in, and shielded out. There is a terminating resistor at the network endpoint. The resistor value needs to match the impedance characteristics of the cable. If the impedance characteristics of the cable are unknown, a 120-ohm resistor should be used. ■ ProfiBUS Bus Conversion Module SST5136 The SST5136 is used in the VME bus, allowing the host to communicate with a ProfiBus network using Profibus DP and FDL. The SST5136 card supports synchronous operation in all modes. It supports standard ProfiBus baud rates of 9.6K, 19.2K, 93.75K, 7.5K, 500K, 750K, 1.5M, 3M, 6M, and 12M. ■ OptoBUS Bus Conversion Module VLI041 2-Serial Port Connection RS232 and RS422/RS485 OPTOBUS and VME Status Indicators ■ The rack includes mechanical parts, a base plate, a fan, a PSU, and a display board for VME bus-based microprocessor systems. III. Network System The system adopts a distributed local area network, including 8 operator stations, 1 database server, and 1 application server. 1. The primary Ethernet uses Ethernet fiber optic cables, twisted-pair network cables, Ethernet fiber-to-RJ45 media converters, and switches. Each PC uses a network adapter to form an industrial Ethernet network. The HPC, engineer station P6, remote maintenance station P7, data server P8, INTOUCH server P10, plate maintenance workstations P3 and P9, and the thickness gauge use the TCP/IP communication protocol. The ACO resource in the P80C program enables successful data communication between each workstation and the HPC, plate gauge, and thickness gauge within the application program. 2. The secondary Ethernet enables communication between the primary Ethernet and the main control station P1, auxiliary control station P2, rolling program station P4, maintenance workstations P5 and P8, and the INTOUCH server P10. 3. N80 Remote I/O Network: The N80 remote I/O network uses 21 N80 communication interface units to connect all N80 remote I/O points, including 64 16-channel digital input modules, 33 16-channel digital output modules, and 8 4-channel temperature input modules. A handheld programmer is used to configure the header address, module quantity, type, and communication parameters of each communication interface unit. The AIO resource module of the P80C program enables successful communication between the HPC and the motor control center, main control console, auxiliary control console, solenoid valves, and remote I/O. 4. PROFIBUS Network: The SST-5136 PROFIBUS communication template is used in the HPC computer control cabinet, configuring the template address and the communication addresses of the mill display instruments ANSS, ANLD, ANED, and ANEG. The PROFIBUS communication program in the ACO resource module of the P80C program displays important process parameters such as mill pressure adjustment, rolling line height, left eccentric roll, and right eccentric roll. 5. The RS485 network uses the VMIVME-7698-345 template in the HPC computer control cabinet. The template address, COM1 and COM2 operating parameters, and the operating parameters of the ANLB and ANRB displays on the mill auxiliary operating console are configured. An RS232-RS485 conversion module is connected, and data is sent via the RS485 communication software in the ACO resource module of the P80C program to ensure correct display of process parameters. 6. The OptoBUS network uses the SST-5136 template. Through the OptoBUS communication card PCO41 (ST connection) of the Advantech IPC-610 EP-250 gateway, and the OPTOBUS INTERFACE communication software in the ACO resource module of the P80C program, normal communication between the HPC, Ethernet, and the drive system is achieved. The IP address configurations for each workstation and control cabinet are shown in Table 2. The system network structure diagram is shown in Figure 3. [align=center]Figure 3 System Network Structure Diagram[/align] IV. Software Control Functions The control system software includes: HPC's VX-WORKS real-time operating system, P80C program development platform (version 2.6h), and configuration software INTOUCH 7.1. ●HPC Control Software The HPC control software consists of the following parts: 1. ACO communication software implements thickness curve, report software, summary and general data communication, Profibus communication for the mill display, thickness curve, report communication, TCP/IP protocol communication, etc. 2. AIO remote I/O implements N80 network communication, input, output, and interface unit control. 3. ASL strip steel drive pressing sequence control implements data curve plotting, task synchronization control, rolling auxiliary sequence control, process sequence control, partial sequence control, and paper winding machine control, etc. 4. ASM steel coil preprocessing implements data curve plotting, input acquisition and simulation, inlet tension, outlet tension control, and monitoring screen interface, etc. 5. The ASU hydraulic synchronous control realizes 200 Pa and 130 Pa water pressure control, filter control, cooling water circulation control, and lubricating oil pump control. 6. The ARE strip drive control realizes uncoiling tension measurement, DC drive sequential control, and AC drive sequential control. 7. The ARF strip shape control realizes strip shape curve plotting and mill #1 intermediate roll position control. 8. The ARG thickness measurement control realizes upper roll pressing position control, thickness measurement, and deviation correction control. 9. The ARP rolling process control comprises step management, inlet/outlet selection, strip shape measurement system, and steel grade characteristic processing. ●HMI Content List V. System Features 1. The Sendzimir 20-roll cold rolling mill computer control system uses the C80-PEC/HPC, a high-performance controller based on the Intel Architecture vxWorks real-time system. It is powerful, has a user-friendly programming environment, and uses an advanced programming language. ■ Fast response (400 µS for VDM6000); ■ Can install multiple processors (up to 4); ■ One processor can handle multiple resources; ■ Multiple loops of all tasks can be handled within one resource; ■ Priorities can be automatically defined during program execution; ■ I/O signals can be simulated and modified; ■ System self-diagnosis; ■ Each processor can connect to Ethernet. 2. The Sendzimir cold rolling mill drive control system adopts the world's advanced high-voltage AC-DC-AC frequency conversion, directly applying the capacitor floating charging method to the rectifier section of the AC-DC-AC frequency conversion, forming a 3400V, 1200A high-voltage, high-current device, which is technologically advanced. Taiyuan Iron & Steel's No. 2 and No. 3 Sendzimir rolling mills are the second and third sets actually in use in the world. 3. The SENDZIMIR cold rolling mill drive control system uses IGBTs (Insulated Gate Bipolar Transistors) for both the frequency converter and the rectifier feedback unit. Its bus connection method is highly efficient, the main circuit is simple, and the capacity of the rectifier-side transformer and the low harmonic current device on the AC input side is small, but it has high requirements for control functions and grid voltage fluctuation amplitude.