The weighbridge is a complete set of automated equipment that realizes dynamic weighing and control through electrical control management and visual human-machine software configuration. The Weighing system uses PLC, and is programmed and controlled according to production requirements. The software adopts human-machine configuration, and through the monitoring system and PLC program, it controls the weight and flow of the materials loaded into the weighing hopper, thereby achieving precise measurement and control. The system has strong stability and high cost performance, and can provide accurate measurement data and control means for various industrial sites' production control and management.

The weighbridge is mainly composed of PLC, communication interface, control host, weighing sensors and conversion circuits. The control host uses PLC control to complete the data acquisition and calculation of the four weighing sensors, and transmits the data through a dedicated communication interface to the PLC, which is displayed on the PLC screen. The communication interface also has an overloading sound and light alarm function. The weighbridge divides the positions within the four guide rods' planes into four different positions. These four positioning points are not on the same straight line, so the positioning conforms to the principle of "four points determine a plane", which makes the positioning accurate and reliable, and improves the precision and reliability of the positioning of the weighing module.

To ensure the accuracy and reliability of weighing in the entire weighbridge, according to the uniformity and accuracy of the force, four Weighing modules are arranged horizontally in the same plane to ensure that the weighing sensors only receive vertical force. The horizontal plate in the positioning seat is designed to be an arc surface on the upper part, so that the weighing module only receives vertical force when bearing the weighing, and the eccentric force is reduced as much as possible. The upper pressure plate of the sensor is connected to the upper weighing module. The main body of the sensor is connected to the lower weighing module. The Electronic scale collects, processes, indicates and outputs the data of the weighing sensor, and the weighing sensor control circuit mainly includes the weighing sensor conversion circuit and the data selection control circuit. The weighing sensor conversion circuit amplifies and processes the millivolt-level electrical signal of the weighing sensor into a frequency or pulse signal that can be remotely transmitted, and controls according to the corresponding relationship of the certain frequency and the weighing. When the PLC measures the frequency of a certain sensor, it converts the corresponding weighing according to the corresponding relationship. The data selection control circuit selects the frequency of a certain sensor through the pin level of the PLC and measures it, and then changes the pin level cyclically to scan all four sensors, and the PLC accumulates all the data to form the weight of the entire truck.

The special protection circuit designed for the weighbridge to prevent PLC from crashing is used to prevent PLC from crashing. The PLC itself has no ability to prevent electromagnetic or power interference, and in industrial site use, it may be subject to electromagnetic interference from various spaces or power sources, which is likely to cause a crash. Once the PLC enters a crashed state, it will not automatically recover and can only be reset by power-on, which brings inconvenience to the on-site application. In the PLC application system, to improve safety and reliability, it is necessary to design a crash prevention path. This circuit can immediately restore operation within 1 second (time adjustable) when the PLC crashes, has no impact on the detection data and usage effect, and can ensure the long-term continuous operation of the PLC or control host.