Tag, also known as electronic tag or smart tag, is a chip with antenna in memory, which stores information that can identify the target. RFID tag has the characteristics of strong persistence, strong penetration of information receiving and transmission, large storage capacity and various types of information. Some RFID tags support read-write function, which can update the information of the target object at any time. The interpreter is divided into two types: Handheld and fixed, which is composed of transmitter, receiver, control module and transceiver. The transceiver is connected with the control computer or PLC to realize its communication function.