Article abstract: This article introduces a kind of mature program, which can conduct multiple instruments networking weighing 
program, in farms and workshop. The amounts of weighing instruments are about 255 units theoretically. Through RS485 networking, 
it can link the dispersion distance of one kilometer instruments together. In practice, our range is about 200 meters, the data 
transmission is normal.

In some occasions, in the case of frequent weighting work and a large amount of manual labor, you can connect the instrument of multiple scales. While getting the weight value, this value is saved in real time through the Internet
Go to the computer. After a period of time, users can call the data from the computer and print the statistical statement. Let the managers accurately grasp the production progress at any time to prevent the occurrence of cutting corners. Typical occasions are production and workshop production. The KH3012 instrument can meet the above production requirements. Kh3012
The controller is a weighing display controller in the field of industrial control. Its consumption weight shows that the analog signal output, RS232/485 interface, and relay output in one. Fully consider the complexity of the industrial site, design and manage the production and management with careful software and hardware, which is suitable for building materials, chemical industry, food and steel industries. Multiple scales are connected through the RS485 network. In practical applications, we have used 12 instruments and can also achieve more scale connections. Use the RS232 RS485 converter to connect the computer and the network. The RS485 requires about the power supply of about the DC12V independent power supply to ensure long -distance voltage drop loss. In theory, when the communication rate is 100kbps below, the longest transmission distance of RS485 can reach 1200m, but the distance transmitted in the actual application is different due to the transmission characteristics of the chip and cable. During the transmission process, the signal can be enlarged by increasing relay, and up to eight relays can be added, which means that the maximum transmission distance of the RS485 can reach 9.6km. If long -distance transmission is needed, optical fiber can be used as the propagation medium, and a photoelectric converter is added with each ends. The transmission distance of the multi -mode fiber is 5km ~ 10km, and a single -mode optical fiber can reach a transmission distance of 50km.
In the design of the instrument software, we have customized a reliable communication protocol. At the scene, after the instrument weight stable, the control switch was opened, and the meter weight was sent to the computer's computer. At the beginning of the design, when the technicians considering that the multiple instrument addresses differently and needed to respond, the technicians designed a way of instruction. After receiving the data of a certain instrument, the upper machine re -verified this data. After returning to the instrument, the instrument is stopped, otherwise it will continue to send it until the correct answer instruction is received. The upper machine is not worthy, and the data is automatically saved. When designing the upper machine software, neither the data is omitted nor the interface, otherwise it will cause the interface to flash, affecting the user's normal viewing data. Need to adopt two data components to update simultaneously, one
Detecting new data in the background, and one is responsible for refreshing the front desk data. In this way, it feels that new data is updated immediately. When new data is still, it is still, and it does not affect other operations of the user.