Preface
With the rapid development of the Internet of Things in China, the Internet of Things has penetrated into various fields, and its application in the industrial field is also very common. The Internet of Things is different from the Internet in that it connects the physical world and the information world through the perception layer. The data collection of the perception layer is the technical basis for reliable and accurate data mining at the application layer of the Internet of Things. Data collection is the most critical technology in the perception layer of the Internet of Things. Currently, commonly used data collection methods include barcode, QR code and RFID technology. How much do you know about RFID ? Morning control will take you to understand.
1. Introduction to the principle of RFID data collection method
RFID is different from barcodes and two-dimensional codes. Both barcodes and two-dimensional codes can be regarded as patterns printed on a piece of paper, coded in black and white bars or grids on the patterns, without chips. RFID is an electronic tag, the information is stored in the chip, the chip can read and write. The printer used is also a specialized printer that can write information on the chip.
The working principle of the RFID system: the information to be sent by the reader or handset is encoded and loaded on a carrier signal of a certain frequency and sent out via the antenna, and the electronic tag entering the working area of the reader receives this pulse signal. Can read the information in the RFID tag, or write information to it. Labels can write information, which is a major advantage of RFID technology. After barcodes and QR codes are printed, they can only be read, and information cannot be written again.
RFID electronic tag: consists of a chip and a built-in antenna. A certain format of electronic data is stored in the chip, which serves as the identification information of the object to be identified and is the real data carrier of the radio frequency identification system. The built-in antenna is used to communicate with the radio frequency antenna.
There are three categories of RFID technology products: passive RFID products, active RFID products, and semi-active RFID products. Passive RFID products do not have batteries. Both active RFID products and semi-active RFID products have batteries. Semi-active RFID products have low battery power and rely on their own battery energy to maintain a standby state when not communicating with the reader.
2. Application characteristics of RFID data collection method
Regardless of the barcode or the QR code, only one tag content can be read at a time. However, with RFID technology, multiple tags can be read at a time, and the reading efficiency is greatly improved. This is an advantage of RFID , and because of this advantage, it has many advantages. The occasion replaced the barcode.
RFID has a different frequency from the operating band to be divided into sub-words, a low frequency (125Khz ~ 134Khz), high frequency (13.56Mhz), UHF (860MHz ~ 928Mhz different standards around the world), microwave (2.45Ghz, 5.8Ghz ). The higher the frequency, the longer the propagation distance, but the weaker diffraction or penetration ability.
The RFID tag can repeatedly add, modify, and delete the data stored in the RFID tag to facilitate the update of information.
When covered, RFID can penetrate non-metal or non-transparent materials such as paper, wood, and plastic, and can perform penetrating communication. The barcode scanning equipment must be close and without obstructions before it can read the barcode.
