The Design Of Accurate Counting And Packaging System Based On PLC

Modern weighing counting system has been widely used in agriculture, scientific research, transportation, internal and external trade and other fields. Weighing counting quality directly affect the quality of the products. The existing methods which are used to weight and count the small quality and large quantity are to count the quantity as the rated quantity of one packing bag. Then, use the rated quantity as reference to count the number of each bag. But because of the error of unit weight and environmental interference, the counting errors arise,which will effect the quality of products. Therefore, according to the question of methods in weighing and counting, the paper based on programmable controller device is suitable for small quality and large quantity of accurate packaging counting system which has a high application value and practical significance.First and foremost, this paper describes the hardware construction and software design of the system, which is mainly composed of Siemens S7-200 AC/DC/RLY, Siemens CPU226 CN, SIWAREX MS weighing sensor, Siemens TP177 micro touch screen, etc.. Through compiling corresponding program by software of STEP7 Micro/WIN,the system will weight and count clamps each time when clamps were put into the pallet, this method effectively eliminates the accumulated error and achieves more accurate count. Then through analog-digital converter of weighing module converts analog quantity into numeric value to calculate. Finally, use the software of SIMATIC Win-cc flexible to design configuration screens and show accurately results of weight and quantity on the touch screen.Secondly, this paper study detailedly to analyze error sources of the system and find a method to decrease error. The error sources mainly include outside interference, equipment precision and clamps’quality error. In view of different errors, this paper puts forward the corresponding solutions. Reliability, accuracy and the stability tests are performed according to the different environmental conditions. Experiments prove that the system has reached the design requirements.Finally, this paper improve the existing model of producing and packaging, and integrate a system with processes of checkout, counting and packaging, then check the accuracy of the system. The paper perfects the existing mode of production and packaging which is based on the integrated system, proposes a new scheme in order to save the cost of production and improves production efficiency of the ultimate objective.