Thread Content
1. Introduction Industrial control configuration software is a software package that enables real-time data collection from devices such as PLCs and field instruments, the issuance of control commands, and the monitoring of the proper operation of the system. It can make full use of Windows’ powerful graphic editing capabilities to display the operating status of monitoring devices in an animated format, enabling the easy creation of monitoring interfaces and the implementation of control functions. It provides a very convenient software development platform for the development of industrial monitoring software, **increasing the efficiency and reliability of software development; as a result, it is widely used in the field of industrial control. Ifix3.5, developed by the American company Intellution, is one such general-purpose configuration software for industrial automation. Ifix3.5 is a configuration software with a fully Chinese interface that runs on Windows 2000 and Windows NT4.0 environments. It integrates the device drivers for popular PLCs both at home and abroad, enabling quick and easy design of industrial control software that meets the requirements of actual installations. In addition, Ifix3.5 also provides the capability for DDE communication with other PC applications (such as Excel and VB), allowing for the easy creation of various reports (including daily reports, shift reports, monthly reports, etc.). On the other hand, Ifix3.5 can also be arranged in a network to exchange data with multiple remote nodes via the TCP/IP protocol. Leveraging Ifix3.5’s powerful graphics and reporting functions, the author designed a computer monitoring system based on Ifix3.5 for Wuhan Petrochemical Plant; this system is capable of displaying and recording data from the field, generating various reports, and providing alarm outputs. 2. System hardware: As shown in Figure 1, the overall structure of this system is a master-slave architecture. A PC is used as the host computer, to which an SA85 communication card is inserted; this card is responsible for facilitating data exchange between the PC and the lower-level PLC. The upper-level computer is an IPC850 industrial PC produced by Advantech, while Ifix3.5 is used as the human-machine interaction configuration software to handle functions such as screen display, report generation, and alarm output. Figure 1 shows a schematic diagram of the hardware structure of the control system. The lower-level controller is a Quantum series PLC produced by Schneider Electric, which carries out the control functions of the computer control system for the entire PP nitrogen production plant. For system security, the author selected 2 host computers; both were equipped with SA85 communication cards and connected to a splitter via dedicated cables. The splitter was then connected to the MB+ interface of the PLCs serving as the slave computers, thereby enabling dual-machine hot backup for the entire system. 3. Software design and configuration of the control system: After the hardware design of the system is completed, the software design for the system is carried out. The monitoring software for the host computer was developed using Ifix3.5 configuration software. It can directly read from and write to all of the PLC’s variables, allowing for the monitoring of real-time data collected. It is capable of continuously monitoring the equipment, and notifies operators of any faults through text, graphics, sound, and other means. Additionally, it can store alarm information, login details, shift handover information, etc., in a database for future reference. To this end, a screen structure as shown in Figure 2 was designed. Figure 2 The software design scheme for the configuration interface is as follows: (1) The Ifix drawing toolkit is used to design the process flow interface. There are mainly 10 screens, including the system overview, air compressor, pre-cooling system, liquid-cooled storage, purification system, distillation tower, Distillation Tower 1, Distillation Tower 2, expander, alarms, and reports. (2) Use Ifix’s database editor to enter the PLC’s I/O points. (3) Establish a connection between the values displayed on the process flow screen and the data of the PLC I/O points in the database. (4) Use Ifix’s charting toolkit to design the historical trend display. Each historical trend screen displays the historical curves of 7 to 8 key parameters, enabling real-time monitoring of important data from the production process. (5) The script program of the button is used to perform functions such as screen switching, parameter setting and control, and mode switching. (6) Establish a report database and edit script programs to implement the system’s reporting functions. (7) Generate real-time parameter reports for the device, providing reporting functions for the following parameters. Real-time parameters are saved to disk every 8 hours; the stored data is retained for one month and can be printed at any time using external peripherals. (8) Prepare cost accounting reports (compiled 15 minutes before shift handover) to track the cumulative values of parameters for nitrogen, purified gas, unpurified air, and circulating water. The main screen of the monitoring system is shown in Figure 3: Figure 3 Main Screen of the Monitoring System. 4. Conclusion This article details the process of using Ifix3.5 configuration software to upgrade the upper-level monitoring system for the PP nitrogen production station at Wuhan Petrochemical Plant. The plant uses 2 S5-115 PLCs to control the daily operations of the main silos. By collecting data from each PLC in real time, this system enables real-time monitoring of the operating status and data of various silos, displaying them through graphical interfaces. It can also collect relevant data for archiving purposes to generate reports, as well as create databases for reports and alarms. The technical challenge in this renovation lies in the setup of the communication configuration; once this is done correctly, the newly added host device can communicate with the PLC, and the rest of the tasks can be completed easily. After the renovation of this system, it operates stably, which greatly facilitates users’ operations and has earned positive feedback from them.