Sorting scale mainly includes mechanical system and measurement and control system two parts, need to complete the weighing module signal acquisition, data processing results of the display and storage functions, as well as to realize the up and down and sorting action of automatic control, which measurement and control system is divided into two parts of the weighing system and the work process control to complete the weighing and data processing, the work process control system through the PLC to achieve the control of mechanical action of the various workstations. The mechanical structure mainly includes three parts, namely, feeding machine, weighing system and grouping mechanism for discharging materials. The loading machine is responsible for transporting the materials supplied by the vibrating hopper to the weighing station for high-precision weighing, and detecting the position of the materials through the load cell to control the operation of the vibrating hopper and the stepping motor through PLC.

The weighing station is responsible for weighing the material and transporting the weighed material to the discharging station, which mainly includes weighing module, pneumatic transportation device and anti-vibration device. The lower material and grouping mechanism is responsible for sorting the weighed material, sending the corresponding weight material to the corresponding group and sending the missed weighing and grouping material to the missed material box.

The sorting system mainly includes the acquisition of weighing signals, data processing, display and storage of results. Weighing signals are transmitted to the industrial computer through serial communication industrial computer is the core of the entire detection system, LabVIEW-based weighing instrument platform to receive the signals sent through the serial port, and through the preparation of the corresponding program to perform data processing, calculations and logical judgments, display and storage of the results of the processing and other functions.

When the gravity of the high-precision measuring module will sink and displace after bearing the measured force, the gravity of the counteraction weighing will increase with the increase of the volume of the weighing it conveys. The measured force and the gravitational force are two vectors in opposite directions on the same vertical axis, when the measured force = gravitational force the weighing will be in equilibrium. When the force is equal to the gravitational force, the weight is in equilibrium. The weight is displaced from the original equilibrium state to the equilibrium state by the measured force, resulting in a certain amount of displacement. This displacement is proportional to the measured force. This converts the measured force into a displacement value that is linearly related to it.

The process control is realized by means of a programmable logic controller (PLC), which stores user-oriented commands such as programs, operations, etc. internally and transmits them via digital or analog input. And through the digital or analog input and output control of the production process is the core part of industrial control.

Checkweigher using programmable logic controller PLC advantages, the work process has a flexible system composition, easy to expand, easy to use, can adapt to a variety of harsh operating environments, anti-interference ability and strong reliability and other outstanding features, the weighing device using PLC as the controller through the PLO control of the weighing and sorting system, to improve the degree of automation of the production line of the poles and the efficiency, and reduce the rate of defective finished products.