The Development Of Automatic Weighing System On Drug Absorbing Moisture

According to drug absorption of moisture weighing equipment field, this paperdesigns a new type of automatic weighing system. It is a device whose drug bared in thecontainer, temperature and humidity of the container is controllable, drug’s weight isincreasing because absorbing moisture from the air. The system is established with PLC,and system designs hardware circuit and software algorithm, finally the system getsaccurate data and drug dynamic adsorption curve. This research has importanttheoretical significance and practical value to drug production and moisture prooftechnology. This topic from National Engineering and Research Center for TCM, thedomestic research is still in its beginning stages.This paper mainly introduces the following two aspects:Hardware design: the whole weighing control system is made up of controlledairtight container, weighing sensors, amplifiers, PLC, EM231, switching power supply,etc. With the help of CPU226, system also selects other modules, so a reasonablehardware system is built. Some devices have specific configuration. System collectvoltage signal on the process of weight change, through signal amplification module,A/D conversion module, the serial port communication, the signal is sent to PLC, PLCread processing data according to the serial port communication protocol, the date candisplay in the PC, thus the system can finish the monitoring task.Software design: According to the requirements of the control process andrequirements, System designs the system program with Visual Basic, system can beestablished between the PLC and PC serial communication mode through the PC/PPIcable as RS232/RS485adapter, then PC can read data as artificial intelligence.Software system mainly realizes interface design, communication design, PLC outputpoint design, automatic/manual weighing design, dynamic adsorption curve generation,database preservation, etc.The results show that drug can absorb moisture in the air, and the system can detecttiny weight change which can be displayed in the interface, PC can get dynamicadsorption curve, and the system is stable.