The metering mixer consists of industrial computer, PLC, industrial weighing control terminal (LYNX), frequency converter, vibration motor, screw feeder, weighing module and so on. The industrial computer provides man-machine interactive interface, and completes the functions of controlling information input, data management, data display, storage, statistics and reports. All the control work is completed by PLC. During the system operation, PLC communicates with the upper computer in real time, so as to ensure the consistency between the data displayed on the interface and the actual data on site. The operating commands and setting parameters issued by the operator on the upper computer can be sent to the PLC for execution in real time.

The screw mixer inputs the weight of the ingredients through the host, generates the weight of various materials according to the ratio of raw materials, and transmits it to the PLC through communication. During the dosing process, dynamic real-time monitoring is carried out, other switch quantities sent from each slave are collected regularly, the weight signal of each material is collected in real time and compared with the given signal to determine the next control scheme, and the weight signal is transmitted to the upper computer.

The vacuum mixer adopts a master-slave batching system with PLC as the main controller and industrial computer as the upper computer, which can meet various requirements of the system and overcome the disadvantages of the above two systems. Operators can input and modify the formula through the keyboard and CRT display, dynamically monitor the production process of batching, and print batching results and production reports in time, so as to realize scientific batching production automation and management. Information such as the weight of each material, the cumulative blanking amount and the given value of each material are displayed on CRT, and relevant database files are formed. When necessary, various management files and reports are printed out.

The mixer adopts a master-slave communication structure, with one-to-many communication between the master and slave machines. The master is in the leading position to realize the communication management and control of each slave machine. The RS-232 asynchronous communication port of the industrial computer is connected with PLC after level conversion, forming a physical channel for communication between the upper and lower computers. The upper system is a master-slave bus type industrial local area network, with the upper computer as the master station of the industrial local area network communication, and all other PLCs connected to the network are slave stations. The upper computer adopts polling method, allocates the right to use the bus, and communicates with the slave stations one by one in a certain order.

The mixer mainly completes batching metering and feeding process control. According to the user login level preset by the operator, PLC manually sets and adjusts the set parameters such as weighing times, counterweight, ratio, impact difference, etc. At the same time, the actual value of each batching and the actual value of under-value, as well as the next target value obtained by PLC operation, weighing times, times to be weighed, ratio, etc., and the system also requires equipment control requirements such as batching interlocking, downward interlocking and upward interlocking.

The weighing mixer adopts an all-Chinese interface, which displays the working state of ingredients graphically and dynamically, and displays the weight of materials in the measuring hopper digitally, which is suitable for the operating habits and knowledge level of operators. Almost all the operation buttons can be clicked on the screen by the mouse, which improves the production efficiency and reduces the labor intensity of workers. Through the Ethernet in the production site, the batching computer in the production site can be networked with the office computer, and the production output statistics and raw material consumption assessment can be paperless. Data can be saved indefinitely.