Design And Research On The Monitoring And Control System Of Traditional Chinese Medicine Distilling Process

The Traditional Chinese Medicine (TCM) is one of the important cultural heritages of our country. TCM distilling process is the important link of producing the Chinese patent drugs and production modernization of TCM. However, for a long time, TCM distilling process had been on lagged status: some important parameters such as temperature, pressure,flux and so on, were controlled by hand, which led to the unstable productions.According to the current situation of TCM distilling process, and considering the actual technologic requirements and actual production needs, in this paper, the overall scheme of IPC-PLC monitoring and control system including the hardware and software frame is built. And then the detailed analyses are gone on from the aspects of lower computer and upper computer respectively.The lower computer uses SIEMENS S7-300 PLC—CPU315-2DP. And with the help of the corresponding programming software STEP7 and the programming language STL and LAD, the lower computer control program is made so that the TCM distilling process can be automatic controlled according to the technologic requirements.Using the high stabilization and good anti-disturbance performance industrial personal computer (IPC) as upper computer, WinCC software, which is also a product from SIEMENS, is used to configure the supervisory software, in order to realize the real-time data-logging, supervising and controlling, as well as various visual HMI such as technologic flow, record checking, alarming, reporting, parameter setting, real-time curving. How to use the Global Script of WinCC to develop the fuzzy self-tuning PID parameters control algorithm is described and the fuzzy self-tuning PID control of temperature was achieved in the monitoring and control system.The practical run results show that the system is designed dependably and practicably, which satisfies the industrial requirements, and reaches the excepted requirements.