Weighing hopper machine detects and samples the weight of material in the metering hopper by the controller, and stops feeding when the weight of material in the metering hopper reaches the upper limit value set for dosage. It reads the main totalization, instantaneous flow rate, set flow rate, weighing instrument status and other related data from the weighing instrument. Weighing instrument status display (zero state, interval state, running state or alarm state), online monitoring and management by computer, with high requirements on weighing speed, weighing accuracy, system compatibility and expandability.

The weighing hopper utilizes PLC interlocking technology to ensure the smooth progress of dosage. After the batching starts, the industrial control machine sends a signal to PLC to start adding materials, PLC controls the frequency converter to drive the motor to add materials quickly, the industrial control host continuously reads the weighing data of the weighing instrument through the serial port, when the weight value is close to the set value, the industrial control host sends the control instruction to PLC to stop adding materials, PLC controls the frequency converter to add materials slowly, by estimating the residue of raw materials on the conveyor in advance, the difference between the set value and the actual added material and the difference between the set value and the actual added material will be displayed in real time, which is the same with the actual added material. By estimating the residual value of raw materials on the conveyor in advance, when the difference between the set value and the actual feeding and the residual value of raw materials on the conveyor are comparable, PLC will issue a stop command, which will be executed by the frequency converter, thus controlling the motor to stop, and after stopping, there is no residual value of raw materials on the conveyor, and the accuracy of the dosing is in accordance with the requirements.

The dosage scale consists of an industrial computer, a PLC, an industrial weighing instrument, a frequency converter, a vibration motor, a mixing machine, a sensor, a conveyor belt and other components. PLC provides human-computer interaction interface, completes the functions of control information input, data management, data display, storage, statistics and reports, etc. According to the operator's instruction, it reads a certain numbered recipe, and then according to the proportion and sequence of ingredients in the recipe, PLC sends out the instruction to start the batching, which makes PLC able to start a specific frequency converter.

Batching scale to achieve material transfer, batching control, formula design, production data management and other functions. And it can realize the collection control of multiple ingredients through the network. With PLC as the next machine ingredients, once the production plan is completed in the entire production process, the computer will weigh each raw material according to the plan, no longer need manual intervention. In this process, the worker only takes the material, and the computer checks the weight through the data sent by the electronic weighing, which reduces the work burden of the worker and improves the work efficiency.

The electrical part of pneumatic batching scale is mainly composed of weighing sensor, weighing instrument, programmable controller (PLC), inverter, industrial computer and printer. In the process of dynamic weighing, the weight signal of the weight sensor on the quantitative weighing hopper is received. When the weight of the material in the hopper reaches each set value, the output I/O quantitative signal to the PLC. PLC collects the quantitative output signal of the weighing instrument, and controls the output frequency of each frequency converter through PLC, so as to control the thickness and fine feeding amount of the corresponding vibration feeder and the switching door action of each weighing hopper.

The weighing hopper system measures through the weighing module, and compares the measured value with a given value (the given value is determined by the ratio of material A and material B) and the measured value, and then transmits the result of the comparison to the PLC's A/D analog module, and then transmits the control signal (4-20mA current signal) through the PLC's D/A analog module to the electric regulating valve, and then controls the servo motor in the electric regulating valve to open the electric regulating valve to control the size of material B inlet. The control signal will control the servo motor in the electric control valve to adjust the opening degree of the electric control valve, so as to achieve the control of the feeding size of material B.

Detection machine can accurately detect the weight of unqualified products in the continuous production line, according to its implementation of on-line judgment or weight automatic sorting control, qualified to return to the original conveyor belt, unqualified will be rejected (or alarm shutdown), and has the classification and statistics according to the settings. The hardware of the weighing system mainly consists of computer, signal detection part, signal conditioning circuit, data acquisition card part, control part and actuator part.

The inspection machine selects the continuous dynamic automatic weighing method to check the net weight of the objects, with alarm or fully automatic removal organization, thus achieving the net weight inspection without shutting down the machine on the production line. It is suitable for the discharge of bags and cartons. When the raw material is transferred to the middle of the weighing platform, the working pressure is applied to the load cell, which deforms and changes the characteristic impedance, outputting an altered pulse signal. This signal is amplified by an operational amplifier and output to a converter, which converts it into a convenient analog signal output to a microcontroller for calculation and manipulation. Based on key commands and its optimization algorithms, such results are exported to the display, which shows information about the net weight of the information object.

The weight detection and selection of the automatic detection machine are completed by the weighing sensor, AD module, PLC and conveying mechanism. PLC reads the real-time weight of the product from the AD module, and calculates the weight of the product under test by analyzing and calculating all the weight data during the whole process of the product under test passing through the weighing conveyor belt. At the same time, PLC will judge whether the weight data obtained is within the required weight range. The machine will start the belt reversal action to remove the weight of the unqualified product.