The Research And Application On Key Technology To Process-control Of Marine Biology Enzyme On S7-300

With the rapid development of science and technology and the increasing depletion of land resources, humankind begin to March into the ancient and strange and unfamiliar field of the marine from exploration and research into the various types of industrial development. Marine biological enzyme will be extensively used in the pharmaceutical, food and feed, aquatic products processing industry, washing, textile, leather and other industries. Therefore, it has broad developing prospects and incalculable potential economic benefits.Marine biological enzyme fermentation automatic control system is the supporting electrical control system of the Institute of Aquatic "Ninth Five-Year" 863 projects (marine biological enzyme demonstration project) which undertaken by Yellow Sea Fisheries Research Institute Chinese Academy of Fishery Sciences. Marine biological enzyme fermentation automatic control system is the major carriers of marine biological enzyme's industrialization, which combines modern industrial automation technology with traditional bio-fermentation technology to achieve automatically optimizing control of the marine biological enzyme fermentation process. Centering on PLC(programmable logic controller),Marine biological enzyme fermentation automatic control system applies field bus, VVVF, HMI, fuzzy control, PID control and other advanced industrial technology to processing control of Marine biological enzyme fermentation. And the key issues of the system is to collect, archive, optimize and control the fermentation process parameters.This thesis focuses on the research and design of the automatic control system of marine biological enzyme fermentation process. The automatic control system uses Siemens PLC S7-315-2DP as a primary master station and sits at the heart position, processing various data and technology flow. Operation staff can use the three OP270 operator panels which are the secondary master stations of the system, to monitor the production process. ET200M, a kind of long-distance I/O module, can collect field signals nearby, which is convenient to connection and debugging. All-digital AC MM440 governor has perfect communication function, which can be connected with PROFIBUS board and becomes a PROFIBUS-DP slave statian. It can respond to the commands from the main station in real time and controls on-the-spot devices directly. At the same time, it can monitor and return the running state of the motor. The CP342-5 communication module, as the intermediate repeater of the PROFIBUS-DP network, can be used to reduce the communication tasks of the master station and shorten the systemresponding time.This thesis describes in detail the designing process of marine biological enzymefermentation automatic control system, including hardware designing and software designing. The hardware includes Siemens PLC hardware selection, hardware configuration and network configuration. The software includes program structure designing and some subroutine designing. In addition, the paper also describes general situation of PROFIBUS, as well as the basic characteristics of PROFIBUS-DP. And it gives a detailed account of how to write communication programs between the main station and ET200M station, as well as between master station and MM440 slave station.