How to improve the multi-tag reading rate of UHF RFID

In the practical application of RFID, it is often required to read a large number of tags at the same time, such as the inventory of the number of goods in the warehouse, the inventory of the number of books in the Library scene, including dozens or even hundreds of tags on the conveyor belt or pallet. Reading of cargo labels. For the situation of most goods being read, the probability of being successfully read is called the read rate.

UHF RFID is generally used when the reading distance is longer and the scanning range of radio waves is wider. Therefore, in the field of logistics and supply chain, UHF RFID technology is chosen worldwide. Therefore, the author will further elaborate on the issue of UHF RFID reading rate.

What are the factors that affect the reading rate of UHF RFID?

In addition to the reading distance and scanning direction mentioned above, the reading rate will also be affected by many other factors. For example, the movement speed of the goods at the entrance and exit, the communication speed between the tag and the reader, the material of the pasted goods and the outer packaging, the way the goods are placed, the temperature and humidity of the environment, the height of the ceiling, and the relationship between the reader and the reader. The influence between devices and so on.

I believe that after reading the above description, you must be able to realize that in the actual scene 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 difficulties that need to be overcome in the implementation of RFID projects .

If you want to improve the reading rate of multi-tags, you have to start from the reading principle.

When reading multiple tags, the reader first inquires, and the tags respond to the reader's inquiries one after another. If there are multiple tags responding at the same time during the reading process, the reader will inquire again, and the inquired tags will be marked to make them "sleep", thereby preventing them from being read again. Like this, the high-speed data exchange processing between the reader and the tag is called congestion control and anti-collision.

To improve the reading rate of multi-tags, the reading range and reading time can be extended, and the number of information exchanges between tags and readers can be increased. In addition, high-speed communication methods between readers and tags can also improve read rates.

However, in real scenarios, the situation is too complicated. For example, sometimes there are metal products in the goods, which may cause the tags to be unreadable at some angles. Therefore, the direction of the antenna and the location of the goods are very important factors, and a reasonable design is required to allow the reader to read the tags from all angles.

Moreover, even if all kinds of work are done well, other unexpected situations may occur, such as the electronic tag itself may be broken.