Filling system through the Electronic scale combined with PLC to automatically weigh the material, liquid material to achieve continuous automatic filling, can improve efficiency, reduce the labor intensity of workers, because each bottle before filling, the electronic scale on the bottle "skin" treatment, eliminate the container tare deviation on the filling result, to ensure the filling accuracy. The filling volume can be easily adjusted by adjusting the setting value of the electronic scale without mechanical adjustment. By pressurizing the liquid storage tank, the filling speed is greatly improved. The pressure control of the liquid storage tank adopts PID control principle, which effectively reduces the pressure fluctuation and ensures the stability of the pressure. Two kinds of filling speed control methods are adopted to improve the filling speed and ensure the filling accuracy. If used in conjunction with the system, one device can simultaneously fill different weights of products, improving the flexibility of the production line and equipment utilization.

The automatic Filling machine is connected with the RS232 serial port of the Weighing system to read the weighing data. When the single chip microcomputer sends the information of reading the weighing data to the weighing system through the serial port, the weighing system will send the data to the serial port of the single chip microcomputer through the RS232 serial port after receiving such information, and the serial port interrupts the subroutine to complete the following operations. When the protocol for reading data is sent, the MCU waits for receiving data, when RI appears high level, it executes the corresponding interrupt service program and serial port interrupt, do not allow the interrupt nesting, and then put the received data in a custom array to receive 14 data, RI is set to 0 after receiving a data to open the serial port interrupt. Then continue to wait for the serial port to interrupt until the 14 data received. On the one hand, the database in the machine must exchange and communicate data between the computer serial port and the lower machine (MCU), on the other hand, it must carry out the relevant operations of the database itself, the filling machine according to the need to develop the bucket ID database, the staff database and the weight database, the bucket ID number stored in the bucket ID database and the bucket regulations, etc. The staff database stores the employee number, password, etc., and the weight database stores the vehicle number of the filling station and the weight of each filling.