The liquid Filling machine converts the received weight value (ASCII code) to a decimal number through the data conversion instruction HEX and stores it in the D100 channel. The CMP comparison instruction is used to compare the converted D100 weight data with the data in the H100 channel (set the benchmark weight). According to the comparison results, the PLC determines whether the current weight is lower than the benchmark weight, equal to the benchmark weight, or higher than the benchmark weight, and then controls the action of the solenoid valve until a quantitative filling is completed. The communication between the PLC and the weighing instrument receives the end signal, and maintains the set state when the program is executed, and the PLC begins to receive the data of the data buffer. After receiving the end sign, the PLC communicates with the weighing instrument through RS232C, and there is no protocol communication between the two. The serial communication parameters of PLC and weighing instrument should be consistent.

The automatic filling machine adopts the image tracking system and the image filling can fully reflect the three-dimensional information, and has the depth and layer sense of the display device. It can intuitively feel the distance and distribution of the objects in the image, so that effective spatial information can be obtained more directly. The Filling system is realized by the movement of the filling valve controlled by the stepper motor. The vibration of the advance motor adopts a wideband pulse modulation mode. The direction signal (DIR) and pulse signal (CLK) are respectively the winding direction of the stepper motor controlled by the level trigger, and the moving direction of the stepper motor is controlled. The pulse signal must be at least 10us in advance in the timing. The pulse signal is triggered by the falling edge. The pulse signal controls the rotation of the stepper motor around the machine, and each pulse corresponds to an Angle of rotation of the machine, which is equivalent to controlling the corresponding distance of the stepper motor to control the moving track of the filling gun valve for filling control.