RFID radio frequency recognition is the use of the radio to transmit the signal, may realize the non-contact information recognition. To make RFID system work normally, at least need to contain electronic tag and reader two parts, electronic tag is the data carrier of the radio frequency recognition system, by the tag antenna and tag special chip composition, RFID reader is read the data of the main equipment. Here we come together to understand, rfid reader workflow is what.

1、What is RFID technology

RFID radio frequency identification is a non-contact automatic identification technology, which automatically identifies the target object through radio frequency signal and obtains relevant data, identification work without human intervention, can work in a variety of harsh environments.

RFID technology can identify high-speed moving objects and can identify multiple tags at the same time, the operation is fast and convenient. Short-distance RF products are not afraid of oil stains, dust pollution and other harsh environments, can be used in such environments instead of bar codes, for example, used in factories on the assembly line to track objects. Long-distance RF products are mostly used in traffic, identification distance can reach tens of meters, such as automatic charging or identification of vehicle identity, etc.

2、RFID system includes what

RFID system contains at least two parts: the electronic tag and the reader. According to the different ways of electronic tag power supply, electronic tags can be divided into active electronic tags (Active tag), passive electronic tags (Passive tag) and semi-passive electronic tags (Semi— passive tag). The active electronic tag is equipped with a battery, the passive radio frequency tag does not have a built-in battery, the semi-passive electronic tag (Semi— passive tag) partly relies on the battery work.

The electronic tag according to the different frequency can be divided into low frequency electronic tag, high frequency electronic tag, ultra-high frequency electronic tag and microwave electronic tag. According to the different package form can be divided into credit card tags, linear tags, paper tags, glass tube tags, round tags and special purpose shaped tags.

RFID reader through the (reader) antenna and RFID electronic tag to carry on the wireless communication, can realize to the label identification code and the memory data read out or write operation. Typical reader  contains high frequency module (transmitter and receiver), control unit and read-write antenna.

3、rfid reader work flow

The electronic label and the read-write realize the space (no contact) coupling of the radio frequency signal through the coupling element, in the coupling channel, according to the time sequence relationship, realize the energy transmission, the data exchange.

RFID reader sends the workflow of the command.

1. The application layer program sends out the command to call the tag identification layer module, the tag identification layer module generates the instruction to be sent to access the tag and sends the instruction to the base band processing module.

2. The baseband processing module encodes and modulates the tag recognition layer command to generate the baseband signal, which is divided into two paths and transmitted through the interface.

3. The data is packaged into a serial baseband signal and sent to the RF front-end module.

4. The serial baseband signal enters the RF front-end module and is modulated to the UHF band after conversion, power amplification and upconversion, and then sent to the band-pass filter for filtering.

5. After filtering, the signal is sent to the power amplifier for amplification and then sent to the antenna to send out.

RFID reader receives the label backscattered data information the work flow.

1. RFID electron tag receives the signal from the reader, obtains the energy to be activated by the power up, starts to execute the reader command, and carries on the judgment whether needs to answer, when needs to answer, sends the answer information to the radio frequency front-end module by the backscattering way through the antenna.

2. The RF front-end module sends the received signal to the band-pass filter for filtering, and after filtering, the carrier signal is restored to the baseband signal and passed in through low noise amplification, down conversion, transformation and other parts.

3. The data is sent to the baseband processing module in the PC through the interface.