A Comprehensive Overview of RFID System.
A Comprehensive Overview of RFID System. - Table of contents:
RFID (Radio Frequency Identification) systems are used to read and write data without physical contact.
RFID system works by transmitting electromagnetic signals stored in a small electronic tag, also known as IC tags, ubiquitous ID systems, or RF tags. This enables the non-contact reading and writing of data from a distance.
What is an ID system?
ID (Identification) usually refers to the unique identification of people and objects.
RFID, like barcodes and two-dimensional codes, is used for identifying objects. Biometrics for uniquely identifying people includes fingerprints, and the iris of the eye.
ID system stands for the Identification System. It is a system to read and identify information on people and things, including AIDC (Automatic Identification & Data Capture).
AIDC uses devices that combine hardware and software and does not require human intervention to identify information obtained from media such as barcodes, 2-dimensional codes, RFID systems, iris, fingerprints, voice, etc.
What is an RFID system?
The radio frequency identification system is a non-contact automatic identification system. It automatically identifies the target object through radio frequency wireless signals and obtains relevant data. It is composed of electronic tags, readers, and computer networks.
The radio frequency identification system uses electronic tags to identify objects. The electronic tags exchange data with the reader through radio waves. The reader can transmit the read-and-write commands of the host to the electronic tag, and then transmit the data returned by the electronic tag to the host. The host The advanced data exchange and management system is responsible for completing the storage, management, and control of electronic tag data information.
The principle and composition of RFID
Basic working principle of RFID system
The reader sends a radio frequency signal of a specific frequency through the transmitting antenna. When the electronic tag enters the effective working area, an induced current is generated to obtain energy and be activated, so that the electronic tag transmits its own coded information through the built-in antenna; The antenna receives the modulated signal sent from the tag and transmits it to the signal processing module of the reader through the modulator of the antenna.
After demodulation and decoding, the effective information is sent to the background host system for related processing; the host system identifies the signal according to the logic operation. The identity of the tag, make corresponding processing and control according to different settings, and finally, send out a signal to control the reader to complete different read and write operations.
Composition of RFID system
In the actual RFID solution, whether it is a simple RFID system or a complex RFID system, some basic components are included. Components are divided into hardware components and software components. From an end-to-end perspective, an RFID system consists of electronic tags, reader antennas, readers, sensors/actuators/alarms, communication facilities, controllers, and application software. From the perspective of function realization, the RFID system can be divided into two parts: the edge system and the software system.
This view coincides with the view of modern information technology. The edge system mainly completes information perception, which belongs to the hardware component; the software system completes the processing and application of information; the communication facility is responsible for the information transmission of the entire RFID system.
The hardware components in the RFID system include electronic tags, readers (including sensors/actuators/alarms and edge interfaces), controllers, and read-write antennas; of course, there are also hosts in the system, application software programs for processing data, and connecting to the network.
Workflow of RFID system
The RFID system has a basic workflow. It can be seen from the workflow that the RFID system uses radio frequency to perform non-contact two-way data transmission between the reader and the electronic tag to achieve the purpose of target identification, data transmission, and control. The general workflow of an RFID system is as follows:
- The reader sends a certain frequency radio frequency signal through the transmitting antenna.
- When the electronic tag enters the working area of the reader antenna, the electronic tag antenna generates enough induced current, and the electronic tag obtains energy and is activated.
- The electronic tag sends its own information through the built-in antenna.
- The reader antenna receives the carrier signal sent from the electronic tag.
- The reader-writer antenna transmits the carrier signal to the reader-writer.
- The reader demodulates and decodes the received signal, and then sends it to the upper layer of the system for related processing.
- The high level of the system judges the legitimacy of the electronic label according to the logical operation.
- The high-level system makes corresponding processing for different settings, sends out command signals, and controls the action of the actuator.
Classification of RFID systems
According to the different functions completed by the RFID system, the RFID system can be divided into four types.
1. Electronic Surveillance Technology
Electronic Article Surveillance (EAS) is a kind of RFID technology that is installed at the door that needs to control the entry and exit of items.
Typical applications of this technology are stores, libraries, data centers, etc. When unauthorized people take items from these places illegally, the EAS system will issue a warning. When applying EAS technology, first attach an EAS tag to the item. When the item is purchased normally or legally removed, the EAS tag will be deactivated by a certain device at the settlement, and the item can be taken away. When an item passes through the doorway equipped with the EAS system, the EAS device can automatically detect the activity of the label, and the EAS system that finds the activity label will issue a warning. The application of EAS technology can effectively prevent items from being stolen, whether it is large items or small items.
With the application of EAS technology, items no longer need to be locked in glass cabinets, and customers can freely watch and check products, which has very important practical significance today when self-selection is becoming more and more popular.
2. Portable data acquisition system
The portable data collection system uses a handheld data collector with an RFID reader to collect data on RFID tags. This kind of system has great flexibility and is suitable for application environments where fixed RFID systems are not suitable, such as 15.6 inch android tablet.
The handheld reader (data input terminal) can transmit data to the main computer system in real-time through radio wave data transmission (RFDC) while reading the data, or temporarily store the data in the reader, and then batch-by-batch Transfer data in batches to the host computer system.
3. Logistics control system
In the logistics control system, fixedly arranged RFID readers are scattered in a given area, and the readers are directly connected to the data management information system. The signal transmitter is mobile and is generally installed on moving objects and people. When objects and people pass by the reader, the reader will automatically scan the information on the label, and input the data information into the data management information system for storage, analysis, and processing to achieve the purpose of controlling logistics.
4. Positioning system
The positioning system is used for positioning in the automatic processing system and supporting the operation and positioning of vehicles and ships. The reader is placed on a moving vehicle, ship, or moving materials, semi-finished products, and finished products in an automated assembly line. The signal transmitter is embedded under the surface of the operating environment, where the location identification information is stored; the reader is generally connected to the Master Information Management System.