| With the developing of the industry the application of PLC in the industrial automation gets more and more important. The PLC control system can lighten the working strength of the workers, reduce the difficulty of the spot management greatly and can enhance the safety factor. So it reflects the principle of the people oriented and upgrades the industrial automation to a new level. In one word, the PLC is a special computer for industry environment application. The PLC provides many I/O interfaces and powerful drive. Because the PLC don't aim at some especial industry application, the hardware of PLC should be chosen and the software should be designed and programmed additionally according to the requires. In the monitoring system, the PLC solves the problems about credibility and safety that many experts care for in industrial field, so it is widely applied as the lower level controller, meanwhile it is a low cost, short period scheme that we design friendly real time displaying windows by using configuration software in the super computer. The author dissertates the design and development for this project under the background of the plant of some oilfield branch for storage and transportation of oil after knowing about the development domestic and overseas online monitoring technique.The paper introduced the design requires of the PLC control system and the techniques and the control flow of the oil extraction joint station. On this basis , the monitoring system of the joint station has designed with WinCC .The real-time monitoring software includes data acquisition, image display, report production and alarm functions, which is a friendly man-machine interface allowing control of operation of the system faster and more user-friendly. Based on Siemens S7-300 a process of acquisition and data processing software has developed. Based on Siemens point-to-point template ,the author makes free Communication Protocol program. The data is integrated in a cybernetic system to make for the on-site supervision, and to reduce the cost of CP341 and Hardware Watchdog. After the installation and the commissioning, the system works steadily and well now. |
