The Research And Design Of Performance Examination System Of Agricultural Products Processing Machines Based On PLC Control

At present, agricultural products processing machines are various in style and complicated in specification in our country. Products examination with traditional method exist the following questions: long measure cycle, heavy work load, low efficiency. In order to make the agricultural products processing machines can reach the performance and requirement that the country stipulates before producing in enormous quantities and putting on market, this article adopts data acquisition technology and PLC control technology to research and design the performance examination system about agricultural products processing machines in foundation the require live and systematic technical indicator.Firstly, this article summed up the importance for the computer control system and PLC in industrial control and analyzed the quality current situation of agricultural products processing machines. Secondly, the article recommended the data acquisition technology and PLC control technology. Thirdly, the article proposed the overall design scheme of the examination system, designed the hardware of the examination system. Data acquisition card PCL813 gathers the data transmitted by the testing scene's each sensor, and then the data are transmitted to the industrial personal computer(IPC) by the data bus PCI of IPC, RS232C realizes the serial communication between the IPC and lower position machine PLC, PLC controls the performance examination system of agricultural products processing machines, RS485 realizes the serial communication between PLC and the variable-frequency drive(VFD), VFD changes the alternative variable frequency motor's frequency, thus which control the flow of raw materials. Fourthly, the paper designed the software of the examination system, including the procedure of PLC controls the examination scene and the procedure of serial communication adopting RS485 serial interfaces between PLC and VFD with the MODBUS communication protocol. The method with RS485 serial interface to control VFD reduced the system to connect up greatly, prevented various possible electromagnetisms in the scene from interfering with the influence on controlling apparatus, and improved effectively systematic anti-interference ability.Adopting 6.5 software, configuration king to make the human machine interface (HMI) in IPC, which made the operation was easy and simple. HMI and PLC procedure two are combined organicly together, that made the system'running is normal and effective, the use is easy, the control is simple, the function is perfect, and the operation is ideal. Fifthly, the data from the operating system were analyzed and dealt with.The performance examination system about agricultural products processing machines has applied to the exam of the rice mill, the operation and test result indicated the system run steadily, every control function of the system can be realized reliably. It proves the scheme of this system is feasible.