In the actual application of RFID, it is often required to read a large number of labels at the same time, such as the inventory of the quantity of goods in the warehouse, the inventory of the number of books in the library, and the reading of dozens or even hundreds of goods labels on the conveyor belt or tray. In the case of most goods' labels being read, the probability of being successfully read is called the reading rate.
In the hope that the reading distance is longer and the scanning range of the radio wave is wider, UHF RFID labels are generally used. Therefore, in the field of logistics and supply chain, UHF RFID technology is chosen worldwide.
The reading rate is not only related to the reading distance and scanning direction, but also affected by many other factors. For example, the movement speed of the goods at the entrance and exit, the communication speed between the UHF RFID label and the reader, the material of pasting the goods and outer packaging, the way the goods are placed, the temperature and humidity of the environment, the height of the ceiling, and the influence between the readers.
I believe that after reading the above description, you must realize that in the actual application of RFID, it is actually very easy to be affected by the external environment, and these different environmental factors are intertwined with each other, which together constitute the key difficulty that needs to be overcome in the implementation of RFID projects. .
If you want to increase the reading rate of multiple UHF RFID labels, you have to start from the reading principle.
During the multi-label reading, the RFID reader performs the query first, and the labels answer the reader’s query successively. If multiple labels respond at the same time during the reading process, the reader will query again, and the queried labels will be marked to make it "sleep" to prevent it from being read again. In this way, high-speed data exchange is processed between RFID readers and labels, which is called congestion control and anti-collision.
If you want to increase the reading rate of multiple labels, you can expand the reading range and prolong the reading time, and you can also increase the number of information exchanges between the labels and the RFID reader. In addition, the high-speed communication method between the reader and the labels can also increase the reading rate.
However, in reality, the situation is too complicated. For example, sometimes the goods contain metal products, which may cause the labels to be unreadable at some angles. Therefore, the direction of the antenna and the placement of the goods are very important factors. A reasonable design is required to make the RFID reader read the labels from all angles as much as possible.
Moreover, even if all kinds of work are done, other unexpected situations may occur, such as the electronic label itself may be broken.