What is an RFID tag?
Table of Contents
- What is an RFID tag?
- Characteristics of RFID tag
- Principle of RFID tag
- Composition of RFID system
- Advantages and disadvantages of RFID Technology
- Types of RFID Tags
- Signal frequency band
- Coupling of electronic tags
- Near field and far field antennas of RFID antenna
- Application of RFID tag
- Standardization of RFID Technology
- Problem of RFID electronic tag
- Design of RFID electronic tag antenna
- Difference between RFID and NFC
- What is the difference between RF tags and bar codes?
- How to use RFID tags in organisms?
- What is an RFID fragile tag
- Anti conflict technology of RFID electronic tag
- How to cancel RFID tag?
- What is an electronic label inlay card
- What is the difference between RFID tag and barcode?
- What is the difference between UPC and EPC?
- What does UHF mean?
- What does EPC mean?
RFID tag is a device for storing digital identification data. It can transmit information to the reader through radio waves to respond to the identification data to the reader. Without manual intervention, RFID technology can identify high-speed moving objects and multiple electronic tags at the same time, which is fast and convenient to operate. RFID tag is a non-contact automatic identification technology. It identifies the target object and obtains relevant data through RF signal. The identification work does not need manual intervention. As the wireless version of bar code, RFID technology has the advantages of waterproof, antimagnetic, high temperature resistance, long service life, large reading distance, encryption of data on the tag, larger storage capacity Storage information can be changed freely. The coding mode, storage, reading and writing mode of electronic label are different from traditional label (such as bar code) or manual label. The storage of electronic label code is stored in read-only or read-write format on integrated circuit; Especially in the reading and writing mode, the electronic tag is realized by wireless electronic transmission. The outstanding technical characteristics of RFID electronic tag are: it can identify a single very specific object, rather than only one kind of object like bar code; Multiple objects can be read at the same time, while bar codes can only be read one by one; Large amount of information stored; Using radio frequency, data can be read through external materials, and bar code must read information on the surface of material medium by laser or infrared.
Characteristics of RFID tag
The identification and reading of RFID electronic tag does not require direct connection.
- RFID electronic tags can be read, written and reused.
- RFID electronic tags are very durable and adapt to various harsh environments.
- RFID reader can read hundreds of electronic tags in one second.
- The data in RFID electronic tag is encrypted and can be locked, and the security performance is very high.
- RFID tags can store more data than barcode tags or barcodes.
- RFID tags can be printed with personalized information such as instructions, bar codes or company names.
- RFID system can be embedded into the company’s original system or other internal systems as a subsystem.
Non directionality: there is no need to align when reading, just within the range of the reader. Uniqueness: each RFID is unique based on chip identification code, so it cannot be imitated. Richness: the electronic tag chip stores more data, with a storage capacity of hundreds of bytes, and can be read and written repeatedly without waste. Simultaneity: it can read several to thousands of tag identification codes and data at a time. Firmness: it can work all day and is not easy to stain or damage. For example, it is used to track objects on the assembly line of a factory. Long distance RFID products are mostly used in traffic, and the identification distance can reach tens of meters, such as automatic charging or vehicle identification. When the RFID industry can reduce the price of tags, it will lead to the ubiquitous smart packet network to track every stage of the supply chain. Store shelves are full of smart label products that can be tracked from purchase to trash can. The shelf itself will communicate wirelessly with the network. Tags are just one part of this large product tracking network. The other two parts of the network will be readers communicating with tags and the Internet, which will provide communication lines for the network. Let’s take a look at the real scene of the system:
- 1. At the grocery store, you bought a box of milk. The milk container will have an RFID tag to store the expiration date and price of milk. When you remove the milk from the shelf, the shelf may display a specific expiration date of the milk, or the information can be sent wirelessly to your personal digital assistant or mobile phone.
- 2. When you leave the store, you will pass through the door with an embedded tag reader. This reader lists the cost of all items in the shopping cart and sends the grocery bill to your bank to deduct the amount from your account. Product manufacturers know that you have purchased their products, and the store’s computer knows exactly how much each product needs to be reordered.
- 3. When you get home, put the milk in the refrigerator, which is also equipped with a label reader. This smart refrigerator can track all groceries stored in it. It can track the food you use and how often you put it back in the refrigerator, and let you know when milk and other foods go bad.
- 4. Products are also tracked when they are thrown into the trash can or recycle bin. At this point, your refrigerator can add milk to your shopping list, or you can program the refrigerator to automatically order these items.
- 5. Your grocery store knows your unique preferences based on the products you buy. You may receive a magazine created for you instead of a general news briefing with a weekly grocery sale. If you have two school-age children and a puppy, your grocery store can use customer specific marketing by sending you coupons for items such as juice boxes and dog food.
In order for the system to work, each product will be given a unique product number. MIT’s automatic identification center is studying electronic product codes that can replace UPC (EPC) identifier. Each smart tag can contain 96 bit information, including product manufacturer, product name and 40 bit serial number. Using this system, the smart tag will communicate with the network called object naming service. The database will retrieve information about the product and then send the information directly to the manufacturer’s computer. The information stored on smart tags will be written in product markup language (PML), which is based on extensible markup language (XML). PML allows all computers to communicate with any computer system, similar to the way web servers read hypertext markup language (HTML), which is a common language for creating web pages. We haven’t finished yet, but RFID tags are more prominent in your life than you may realize. Wal Mart and bestrol are just two main commodities that use RFID tags for inventory and marketing. An automated system called intelligent software agent manages all data in and out of RFID tags and will perform specific operational processes, such as classifying items.
Principle of RFID tag
After the RFID tag enters the magnetic field, it receives the RF signal sent by the interpreter, With the energy obtained by the induced current, it sends the product information (passive tag) stored in the chip, or actively sends the signal of a certain frequency (active tag); after reading and decoding the information, it is sent to the central information system for relevant data processing.
Composition of RFID system
RFID system is mainly composed of the following three parts:
- (1) Tag. It is composed of coupling elements and chips. Each tag has a unique electronic code. The high-capacity electronic tag has a user writable storage space and is attached to the object to identify the target object.
- (2) Reader. A handheld or fixed device that reads (and sometimes writes) label information.
- (3) Antenna. Transmit RF signals between tags and readers.
Advantages and disadvantages of RFID Technology
Advantage of RFID Technology: RFID chip and RFID card reader have strong resistance to water, oil, chemicals and other substances. The reading of information is not limited by the size and shape of the chip, and does not need to match the fixed size and printing quality of the paper in order to read the accuracy. Moreover, RFID tags are developing towards miniaturization and diversified forms to be applied to different products. RFID technology is more accurate and more flexible than traditional intelligent chips. Can achieve penetrating and barrier free reading. RFID chip tags can repeatedly add, modify and delete internally stored data to facilitate the update of information. The internal data content is protected by password, so that its content is not easy to be forged and altered. RFID chip has a large data capacity, and with the development of technology, the capacity still tends to increase. Disadvantages of RFID Technology: Insufficient technical maturity. RFID technology has appeared for a short time and is not very mature in technology. Because UHF RFID electronic tag has the characteristics of retroreflection, it is difficult to apply it in metals, liquids and other commodities. High cost. The price of RFID electronic tag is higher than that of ordinary bar code tag, which is dozens of times that of ordinary bar code tag. If the use is large, the cost will be too high, which will reduce the enthusiasm of the market to use RFID technology to a great extent. Security is not strong enough. The security problems faced by RFID technology are mainly manifested in the illegal reading and malicious tampering of RFID electronic tag information. Technical standards are not unified. At present, RFID technology has not formed a unified standard, and a variety of standards coexist in the market, resulting in the incompatibility of RFID tags of different enterprise products, which leads to the confusion of the application of RFID technology to a certain extent. Once the RFID tag approaches the reader, it will automatically send a message unconditionally, which can not confirm whether the RFID reader is legal or not. For example, in people’s daily life items, but because the owner of the item (such as clothing) may not be able to detect that the item has been embedded with an electronic label in advance and that it may be scanned, located and tracked uncontrollably, this is bound to infringe on personal privacy. The key to the invasion of personal privacy lies in the basic function of RFID tag: the identification (ID) or identification code of any tag can be arbitrarily scanned remotely, and the tag automatically and indiscriminately responds to the instructions of the reader and transmits the stored information to the reader. Objects or environment containing metal and moisture will affect RFID. The open frequency bands of various countries are different, and there are still problems of consistency.
Types of RFID Tags
RFID tags can be found everywhere in life, most commonly in various industries such as tickets, clothing, security, etc. For the application of each industry, the type of choice is different.
With or without power battery
Active RFID tags by the built-in battery to provide energy, different tags use different numbers and shapes of batteries. Advantages: the role of distance, active RFID tags and RFID readers between the distance can reach dozens of meters, or even up to hundreds of meters. Disadvantages: large size, high cost, the use of time is limited by the battery life, the manufacturer’s ideal indicators for 7-10 years, but because each card used every day and the environment is different, the actual project, some cards can only use a few months, some cards can be used for more than 5 years.
Passive RFID tags do not contain a battery, its electrical energy from the RFID reader to obtain. When the passive RFID tag is close to the RFID reader, the passive RFID tag’s antenna will receive the electromagnetic wave energy into electrical energy, activating the chip in the RFID tag and sending out the data in the RFID chip. Advantages: small size, light weight, low cost, long life, life assurance of more than 10 years, maintenance-free, can be made into different shapes such as thin sheets or hanging buckles, applied to different environments. Disadvantages: because there is no internal power supply, so the distance between the passive RFID tag and RFID reader is limited, usually within a few dozen centimeters, generally requires a larger power RFID reader.
Sending signal timing
Active RFID tag Active RFID tags rely on their own placement of energy sources such as batteries to actively send data outward. Passive RFID tags Passive RFID tag from the received RFID reader to send electromagnetic waves to obtain energy, activated to send data outward, so that RFID can read the data signal. Semi-active RFID tags Semi-active RFID tags own battery and other energy sources only to provide RFID tags in the circuit, and not actively send data signals to the outside, when it receives the RFID reader to send electromagnetic wave activation, before sending data signals to the outside.
Data reading and writing type
Read-only RFID tag
The content of read-only RFID tags can only be read and not written. Read-only RFID tags can be further divided into: read-only tags, one-time programmable read-only tags and reprogrammable read-only tags. Read-only label content has been written in the label factory, in the reader identification process can only read out not write, read-only label internal use of read-only memory (ROM), read-only label belongs to the label manufacturer commissioned by the customer to customize a class of tags. The content of the one-time programmable read-only label is not written before leaving the factory, but is written through programming before use, and can only be read out and not written in the process of reader identification; the internal use of the one-time programmable read-only label is programmable read-only memory (PROM), programmable array logic (PAL); the one-time programmable read-only label can write commodity information through the label code/printer. The content of the repeatable programmable read-only label can be reprogrammed to write after erasure, but it can only read out and not write in the process of reader recognition; the internal use of the one-time programmable read-only label is erasable programmable read-only memory (EPROM) or general array logic (GAL).
Read-write RFID tag content in the identification process can be read out by the reader, can also be written by the reader; read-write RFID tag internal use of random access memory (RAM) or electrically erasable programmable read-only memory (EEROM). Some tags have 2 or more memory blocks, the reader can be programmed to write the contents of different memory blocks respectively.
Signal frequency band
According to the RFID tag operating frequency for classification, can be divided into: low frequency (LF), high frequency (HF), ultra-high frequency (UHF), microwave (MW) four categories. As the RFID operating frequency selection will directly affect the chip design, antenna design, working mode, the role of distance, reader installation requirements, therefore, to understand the characteristics of RFID tags under different operating frequencies, for the design of RFID application system is very important.
Low-frequency tag typical operating frequency of 125kHz ~ 134.2kHz. low-frequency tags are generally passive tags as described above, through the inductive coupling method, from the reader coupling coil radiation near field to obtain the working energy of the tag, read-write distance is generally less than 1 meter. Low frequency label chip cost is low, suitable for close range, low transmission rate, data volume is small application, such as access control, time and attendance, electronic billing, electronic wallet, parking lot fee management, etc.. Low-frequency tags operate at a low frequency and can penetrate water, organic tissue and wood, and their appearance can be made into stud type, collar type, pill type or injection type, suitable for cattle, pigs, carrier pigeons and other animal identification.
The common operating frequency of the medium-high frequency tag is 13.56MHz, and its working principle is basically the same as that of the low-frequency tag, which is a passive tag. The working energy of the tag is obtained from the radiation near field of the coupling coil of the reader through inductive coupling method, and the reading and writing distance is generally less than 1 meter. Medium-high frequency tag can be easily made into a card structure, typical applications are electronic identification, electronic tickets, and campus card and access control system identification card. China’s second generation ID card embedded within the 13.56MHz RFID chip in line with the ISO/IEC14443B standard.
UHF RFID tags and microwave RFID tags are usually referred to as “microwave tags”, a typical UHF operating frequency of 860MHz ~ 928MHz, microwave segment operating frequency of 2.45GHz ~ 5.8GHz. microwave tags are mainly passive tags and active tags of two types. Microwave passive label working frequency is mainly in 902MHz～928MHz; microwave active label working frequency is mainly in 2.45GHz～5.8GHz. microwave label works in the far field area of reader antenna radiation. Because of the UHF and microwave section electromagnetic wave an important characteristic is: the line-of-sight transmission, the UHF and microwave section radio wave bypassing ability is weak, send antenna and receive antenna can’t have object blocking between. Therefore, the read-write antenna used for UHF and microwave RFID tag is designed as directional antenna, only in the antenna directional beam range of the electronic tag can be read and write. The reader antenna radiation field provides energy for the passive tag, the passive tag working distance is greater than 1 meter, the typical value is 4 ~ 7 meters. The reader antenna sends the read-write instruction to the active label, and the active label sends the label stored identification information to the reader. The maximum working distance of the active label can exceed one hundred meters. Microwave tags are generally used for long-distance identification and identification of fast-moving objects. For example, the close range communication and industrial control field, logistics field, railroad transportation identification and management, and the highway non-stop electronic toll collection (ETC) system. Comparison of RFID frequency spectrum
Package type style
Sticker RFID tags are generally composed of face layer, chip and antenna circuit layer, adhesive layer and bottom layer. Sticker RFID tags are inexpensive, have a sticker function, and can be directly attached to the object to be identified, and the face layer can often be printed with text.
Plastic RFID Tags
Plastic encapsulated RFID tags use a specific process with a plastic substrate (ABS, PVC, etc.) to encapsulate the chip and antenna into tags of different shapes. The plastic encapsulated RFID tags can be in different colors, and the encapsulation materials are generally able to withstand high temperatures.
Glass encapsulated RFID tags will chip and antenna encapsulated in a different shape of the glass container, forming a glass encapsulated RFID tags. Glass encapsulated RFID tags can be implanted in animals for animal identification and tracking, as well as the management of precious fish, dogs, cats and other pets, and can also be used for identification of firearms, helmets, wine bottles, molds, jewelry or key chains.
Metal-resistant RFID tags are RFID tags based on the addition of a layer of anti-metal materials, this layer of material can avoid the tag attached to metal objects after the failure of the situation, anti-metal material is a special anti-magnetic absorbing material encapsulated into the electronic tag, from the technical solution to the electronic tag can not be attached to the metal surface using the problem, the product can be waterproof, acid-proof, alkali-proof, collision-proof It can be used in outdoor.
The coupling of electronic tags is to transmit different signals in different ways. The working distance between RFID tag and reader in RFID system is an important problem in the application of RFID system. Usually, this working distance is defined as the distance between RFID tag and reader that can reliably exchange data. The operating distance of RFID system is a comprehensive index, which is closely related to the matching of RF tags and readers. According to the distance of RFID system, the coupling between RFID tag antenna and reader antenna can be divided into three categories.
- (1) Close coupled system. The typical operating range of the system is 0 ~ LCM. In practical applications, it is usually necessary to insert the RF tag into the reader or place it on the surface of the reader antenna. The close coupling system uses the contactless spatial information transmission RF channel composed of inductive coupling (closed magnetic circuit) between the RF tag and the reactive near-field region of the reader / writer antenna. The working frequency of close coupled system is generally limited to any frequency below 30MHz. Because the electromagnetic leakage of the close coupling mode is very small and the energy obtained by coupling is large, it is suitable for the application system with high security requirements and no requirements for action distance (such as electronic door lock).
- (2) Teleconnection system. The typical operating distance of teleconnection system can reach LM. Teleconnection system can be subdivided into two types: near coupling system (typical action distance is 15cm) and sparse coupling system (typical action distance is LM). The typical working frequency of teleconnection system is 13.56MHz, and there are also some other frequencies, such as 6.75mhz, 27.125mhz, etc. The main difference between remote coupling system and close coupling system is that the power of inductive coupling is different, so the coupling distance is different. Remote coupling system is still the mainstream of low-cost RFID system.
- (3) Remote system. The typical operating distance of long-distance system is 1 ~ 10m, and individual systems have a longer operating distance. All long-distance systems use the electromagnetic coupling (electromagnetic wave emission and reflection) between RF tag and reader antenna to form a contactless RF channel for spatial information transmission. The typical operating frequencies of remote system are 915MHz, 2.45GHz and 5.8GHz. In addition, there are some other frequencies, such as 433MHz. The RF tag of remote system is divided into passive RF tag (without battery) and semi passive RF tag (with battery) according to whether it contains battery or not. In general, the operating distance of the RF tag containing the battery is farther than that of the RF tag without the battery. The battery in the semi passive RF tag does not provide energy for the data transmission between the RF tag and the reader, but only provides energy for the RF tag chip to serve the reading and writing of stored data. In general, the long-distance system adopts the reflection modulation mode to realize the data transmission from the RF tag to the reader. Long distance systems generally have typical directionality, and the cost of RF tags and readers is still at a high level. From a technical point of view, the long-distance system meeting the following characteristics is an ideal RFID system: the RF tag is passive and can be read and written wirelessly; RF tag and reader support multi tag reading and writing; It is suitable for the recognition of high-speed moving objects (the moving speed of objects is greater than 80kin / h); Long distance (reading and writing distance is greater than 5-10m); Low cost (can meet the requirements of one-time use).
Near field and far field antennas of RFID antenna
The electromagnetic field around RFID antenna can be divided into near-field and far-field. Generally, the near field is defined as up to one wavelength around the antenna (λ). The two segments of RF field, near field and far field have different energy, so they usually need corresponding antenna types to obtain the best reading range. (near field is mainly magnetic, while far field has electrical and magnetic components). The communication between RFID tag and RFID reader (through antenna) is carried out using a process called electromagnetic coupling. There are two types of coupling – inductance and capacitance. Inductive: The near-field antenna uses inductive coupling, which means that it uses a magnetic field to excite RFID tags. A magnetic field is generated in the near-field region, allowing the antenna of the RFID reader to energize the tag. The tag then responds by generating interference in the magnetic field picked up and decoded by the reader. Capacitance: The far-field antenna uses capacitive coupling (or propagation coupling) to excite the RFID tag. Capacitive coupling occurs when the antenna of the RFID reader propagates RF energy outward and uses energy to excite the tag. Then, the tag sends a part of the RF energy back to the antenna of the reader as a backscattering response. With low profile and small profile, the near-field antenna is very suitable for short reading range applications. Different from the far-field antenna emitting propagating electromagnetic field, the near-field antenna generates local magnetic field. In addition, the near-field antenna is usually not as strong as the far-field antenna, which is usually used in indoor environment. Due to the less use of near-field antennas, the options available for deployment are limited. Far field antennas come in a variety of shapes and sizes and can usually read labels up to 30 feet away in ideal conditions between a few centimeters. There are many options when selecting far-field antenna (such as linear or circular polarization, varying gain) and indoor or outdoor use. Due to the increased reading area when using far-field antenna, stray tag reading (i.e. reading unexpected RFID tags) is often a common problem.
Application of RFID tag
RFID electronic tag has been widely used in modern people’s daily life. In many big cities, by rail transit, you can easily transfer between different lines by buying a one-way ticket with RFID electronic tag at one time; When you borrow books in the library, you don’t have to go through the borrowing procedures with the librarian, but just enter the password on the automatic borrowing and returning system, and then easily borrow the books you want; In many hypermarkets and supermarkets, RFID tags can effectively prevent someone from taking away goods without payment. In hospitals, electronic labels are widely used. For example, newborn babies look very similar, which is easy to cause misunderstandings about recognizing the wrong baby. On TV, there are often hospital nurses or parents holding the wrong child decades ago, which leads to a lot of family tragedies, so they can accurately identify their identity, so as to avoid mistakes. In addition, there is an electronic medical record, through which doctors and nurses can clearly know the medication of patients during ward rounds. In this way, not only the work of medical staff will be orderly, but also medical people and their families can avoid a lot of trouble. The wide application of RFID tag has brought a lot of convenience to people’s life. I believe it will be applied to more and more useful places in the near future. At that time, our life will be better and people can save a lot of time to do more meaningful things. In recent decades, the theory of RFID technology has been enriched and improved, and active, passive and semi passive electronic tags have developed rapidly. Single chip electronic tags, multi electronic tag reading, wireless readable and writable, remote identification of passive electronic tags, and RFID suitable for high-speed moving animals are becoming a reality. The application fields of electronic labels include the following aspects.
- Logistics: cargo tracking, automatic information collection, warehousing application, port application, postal express in the logistics process.
- Retail: real time statistics of commodity sales data, replenishment and anti-theft· Manufacturing: real time monitoring of production data, quality tracking and automatic production.
- Medical industry: medical device management, drug management and his system.
- Identification: e-passport, ID card, student card and other electronic documents.
- Anti counterfeiting: anti counterfeiting of valuables (cigarettes, wine, drugs) and tickets.
- Asset management: management of all kinds of valuable, large quantity, high similarity, or dangerous goods and other assets.
- Transportation: expressway toll management, vehicle identification and management of taxis and buses.
- Food: management of freshness of fruits, vegetables and fresh food.
- Animal identification: identification and management of domesticated animals, livestock and pets.
- Library: the application of book management in bookstores, libraries and publishing houses.
- Automobile: manufacturing, anti-theft, positioning, car keys.
- Aviation: manufacturing, passenger tickets, luggage and parcel tracking.
- Military: identification and tracking of ammunition, firearms, materials, personnel and vehicles.
RFID intelligent management solution for garment factory
- 1. Give each garment a unique identification. Search this ID to check the information records of the product in terms of production, logistics and sales, so as to realize the timely tracking management of single goods;
- 2. The warehouse headquarters receives the goods, uses the RFID receiving channel equipment to quickly scan the whole box of goods, generates and prints the packing list, automatically interfaces with the ERP system, and records the list of each box of goods in the database;
- 3. For warehouse delivery, use RFID equipment to quickly scan the whole box of goods, check the scanning results and delivery notice, generate and print the goods or delivery list of each box, and record the delivery time, destination, agent number and other commodity attributes and commodity flow information associated with each RFID electronic tag in the database;
- 4. Downstream agents are also equipped with RFID scanning equipment to access the brand ERP software system through the network, which can perform the same operation, fast and fine storage management, and collect commodity flow information of dealers and retail stores. Customers, agents and dealers at all levels can share data and coordinate management at the same time;
- 5. When picking or storing inventory in the warehouse, the RFID handheld terminal can quickly select the target goods to avoid wrong picking, missing or more picking; Inventory does not need one operation to achieve efficient inventory;
- 6. When the brand or dealer market regulatory authority needs to check suspicious goods, use the RFID handheld terminal to scan the electronic label in the goods, so as to query the commodity flow, orders, orders and other information, and timely identify the authenticity of the goods and channel ownership;
- 7. The RFID tag in each piece of clothing is stored in the information with password protection. Only the system in the legal RFID equipment can correctly capture or rewrite the tag information. Illegal equipment cannot be collected to ensure safe and unique information.
RFID library management system
With the continuous development of science and technology, the continuous progress of society and the continuous promotion of information construction, the requirements for the quality of library management are higher and higher. Jietong technology combines the traditional book management mode with the most advanced RFID technology to form a more intelligent RFID book management system. Through UHF UHF RFID equipment, it can easily improve the management efficiency and improve the book borrowing rate; Effectively reduce the labor intensity of managers; Further simplifying the procedures for readers to borrow and return books can greatly improve the efficiency of book inventory and sorting.
RFID library management system includes: label conversion system, self-service borrowing system, self-service return system, intelligent search system, cart inventory system and security door detection system.
At present, the main problems in library management are: the continuous growth of the volume of books, the expansion of reader service demand, limited budget and personnel, more forms of materials, cumbersome management methods and low work efficiency. At this time, the necessity of RFID library management system becomes particularly important.
- 1. It simplifies the procedures for readers to borrow and return books, shortens the book circulation cycle, improves the book borrowing rate, improves the humanized service level of the library, gives full play to the public service function of the library, and is welcomed by the majority of readers.
- 2. It provides a new inventory mode for the library, reduces the labor intensity of managers, and greatly improves the efficiency of book inventory and wrong shelf book sorting.
- 3. Make the search of wrong shelf books more fast and convenient, further tap the potential book resources and improve the utilization rate of books and materials.
- 4. The safety door is placed at a wider distance, and readers can get in and out more freely. Because the RFID Security door will not produce false alarm, unnecessary disputes between readers and managers are avoided, and the relationship between readers and managers is harmonious.
System implementation benefits
- 1. Improve management efficiency;
- 2. It improves the borrowing rate of books;
- 3. It has improved the humanized service level of the library;
- 4. It reduces the labor intensity of managers;
- 5. It simplifies the procedures for readers to borrow and return books;
- 6. Greatly improve the efficiency of book inventory and wrong shelf book sorting.
RFID wristband is a kind of wristband, which specifically refers to the identification wristband embedded with RFID RFID chip. Working principle of RFID wristband: radio frequency identification (RFID), also known as radio frequency identification, is a communication technology, which can identify specific targets and read and write relevant data through radio signals without establishing mechanical or optical contact between the identification system and specific targets. Working mode of RFID wristband: similar to bar code scanning, RFID wristband electronic tag has a complete set of use system. The RFID wristband tag with identification information written is non-contact read by the RFID reader and writer, and the content can be displayed on the reader and writer. If connected to the system, more requirements can be done. Such as product warehousing and access control. Application place of RFID wristband: RFID wristband tag is widely used in all-in-one card, catering consumption, attendance management, swimming pool, washing center, sauna center and entertainment place, warehouse management, airport parcel, parcel tracking, hospital patient identification, delivery, baby identification, prison management, guardianship center management, personnel location, etc. It looks like an RFID wristband watch. It can be used almost whenever there is personnel identification or item identification management. RFID medical wristbands are also widely used in the medical field, which can not only effectively and accurately identify patient information, but also better protect patients’ privacy. Some RFID medical wristbands are used for printing and RFID identification. This RFID wristband hand card is printed by RFID medical wristband printer to meet more needs.
Dual core RFID helps new technology of bus passenger flow statistics
The traditional bus passenger flow statistics methods use infrared, video and other passenger flow counting methods, but once these statistical methods encounter a large passenger flow, there will be wrong statistics, which is difficult to achieve the real data. The technology adopts dual core RFID integration and dual functions of collecting tariff and personnel statistics card, realizes the automatic collection of bus passenger flow information, solves the problem of cumbersome and time-consuming collection of bus passenger flow information, and will help promote the city’s intelligent public transport system and urban smooth traffic project. As an important data of public transport management and operation, passenger flow is not only an indispensable element of intelligent public transport system, but also the core data concerned by urban public transport managers. However, the existing technology can not solve the problem of obtaining accurate data with low investment, which has become a key technology problem to be solved in the intelligent public transportation system. The active RFID system actively sends the information of the dual core smart card to the number of people acquisition point at an interval of one time, judges and reports the location of the monitoring card to the system, and the number of people acquisition system replies to the information of the smart card. If the smart card has been sent for many times and has not been replied, it will enter the sleep state, reduce the power consumption of the system and prolong the service time of the system power supply. The theoretical service life of dual core RFID can reach 11 years, and the recognition rate tends to 100%. It has become the leading key technology of bus passenger flow statistics in China. This technology comprehensively improves the rationality of bus dispatching, realizes the application of Internet of things technology in public transport system, lays the foundation for the intellectualization of urban public transport system, promotes the modern development of public transport, brings great convenience to citizens’ travel, and brings immeasurable economic and market effects to urban development, It has comprehensively promoted the smooth flow and fine management of the city. Stereo parking garage and RFID non parking automatic identification system With the increasing shortage of urban land resources, the construction cost of parking lot will increase. How to use the limited space to create more parking spaces is an important business goal of the parking lot. Three dimensional mechanical garage came into being. It is a parking mode that uses mechanical equipment to improve the number of parking per unit area. It has a development history of decades in European and American countries, and the technology has been quite mature. In recent years, in some large and medium-sized cities such as Shanghai and Beijing, three-dimensional parking garages have begun to be vigorously promoted. The biggest advantage of the three-dimensional parking garage is that it occupies less land and has more parking. Compared with the traditional parking lot, 4 ~ 6 cars can be parked in one parking space; It is easy to pick up and place the car. It only takes tens of seconds to stop or pick up the car at a single time, and has high safety and stability; The construction cost is low. The manufacturing cost of each berth is only about 30000 yuan. If the number of floors is small, the cost can be lower. In order to further improve the efficiency of three-dimensional parking garage, RFID technology is introduced, which is referred to as RFID intelligent parking lot management system. It operates based on the process of users’ parking and picking up. Through RFID vehicle tag or electronic license plate, user information, vehicle information, vehicle entry and exit time, parking time, designated parking space number, parking path, payable fees, etc. are entered into the database for unified management, so as to realize the query and storage functions. Through subsystems such as import and export control management system, parking space and guidance management system and billing management system, check vehicle information, guide vehicles to parking space, realize non parking charging and maximize the utilization of parking space resources. Then the data information such as charge management, parking guidance and vehicle identification safety monitoring are established on the same data platform, and each subsystem is effectively integrated into a unified parking lot intelligent management system. This is: RFID non-stop automatic identification system. It organically combines RFID technology, computer control technology and billing software system to realize automatic identification of access vehicles, automatic gate control and automatic billing / deduction, so as to fully realize intelligent vehicle access control. It has played a certain role in promoting the orderly development of the industry.
Application of RFID in laundry industry
At present, hotels, hospitals, baths and professional washing companies are facing thousands of processes such as handover, washing, ironing, sorting and storage of work clothes and linen every year. How to effectively track and manage the washing process, washing times, inventory status and effective classification of each piece of linen is a great challenge:
- The paper washing task handover is complicated and difficult to query;
- Because of the fear of cross infection, the statistical work on the quantity of some linen to be washed cannot be carried out, and the washed quantity does not match the task, which is prone to commercial disputes;
- Each step of the washing process cannot be accurately monitored, and the linen is missing treatment;
- The washed linen is accurately classified to save storage space;
- The minimum safety stock of each piece of cloth cannot be accurately arranged.
The introduction of RFID radio frequency identification technology will make the user’s laundry management more transparent, improve the work efficiency, and solve the persistent management problems that could not be realized by other technologies in the past, such as the statistics and handover of a large number of cloth and grass to be washed. The scheme is to sew a button like (or label like) electronic label on each piece of cloth. The electronic label has a globally unique identification code, that is, each piece of cloth will have a unique management identification until the cloth is scrapped (the label can be reused, but does not exceed the service life of the label itself). In the whole linen use and washing management, the use status and washing times of linen will be automatically recorded through RFID reader. It supports batch reading of labels during washing handover, making washing task handover simple and transparent and reducing business disputes. At the same time, by tracking the washing times, it can estimate the service life of the current cloth for users and provide prediction data for purchase plans.
Standardization of RFID Technology
RFID standardization began in 1995, By the international organization for Standardization (ISO) and the International Electrotechnical Commission (IEC) organize the joint technical committee to carry out this work. A series of RFID technical standards issued by ISO / IEC can be divided into four categories: technical standards, data structure standards, equipment performance standards and application standards. In addition, they also include some specifications. From the content of RFID technical standards formulated by ISO / IEC, they are based on RFID coding, air interface protocol, reader / writer protocol and other basic technologies Based on the standard and data structure standard, the specific performance requirements such as use conditions, label size, label pasting position, data content format and use frequency band are defined, and the application standards are formulated in terms of other functions such as data integrity and manual identification according to the application field. The RFID technology standard formulated by ISO / IEC is of great significance in universality. It provides a basic framework, takes into account the characteristics of different application fields on the principle of ensuring interoperability and interoperability, and meets the specific requirements of various application fields. EPC global is the world’s second largest RFID standardization organization established by the United States unified code Association (UCC) and the international article coding Association (EAN). The center and many enterprise members have jointly formulated the EPC global technical standard, which focuses on the “Internet of things” Automatically identify the data carrier and content of infrastructure and identification, realize the exchange and sharing of commodity information on the basis of open technology and computer interconnection, and solve the transparency and traceability for logistics supply chain. EPC global is committed to establishing a standardized service network for global electronic label users, which has become the de facto largest standard in the industry and has been widely used. At present, EPC global also submits some of its technical standards to ISO in order to become international standards, so as to make its technical standard system more competitive. The world’s third largest RFID technology standard is drafted by the ubiquitous center led by the Ministry of economy and industry of Japan, and its technology alliance members are mainly Japanese manufacturers. The ubiquitous center organization and its members reject the EPC global technical standards. The RFID related standards formulated by the organization also build a complete standard system and have their own ucode coding system to maintain independence and compatibility. The focus of this system is to pay more attention to the security performance of network and application system. In addition to these three RFID technology standards organizations, there are also aim global, that is, the global Automatic Identification Organization and the third world standards organization ip-x to jointly promote the future Internet of things technology system.
Problem of RFID electronic tag
RFID electronic tag application certainly still exists some short-term difficult to solve the problem.
- (1) Cost. RFID electronic label is after all electronic product, each label is a complete electronic circuit, its cost is several times or dozens of times higher than bar code, magnetic stripe. This is caused by the electronic label almost all identity recognition occasions have demand, but the real realization of the main reason is very little. Such as the occasion of one-time use is inconvenient to use, such as the retail industry supermarket goods, may some goods itself is not as high as the value of an electronic label, such occasions use electronic label is not very realistic. And the manufacturing industry production line, can be mounted to the electronic label “drag plate” on repeated use, so that the cost to each component is relatively very low. Again such as does not stop the charge label, although is not the “tow tray” type repeated use, but can be long-term use, amortized to each use of the cost is also very low, these occasions will be easy to realize the application of electronic label.
- (2) Data basis. RFID electronic tag technology application is based on database management, which requires the corresponding management application system must have standardized, unified data form, need to all management data for a change.
- (3) Business process. Due to the use of high-tech means, RFID electronic tags are used to a greater or lesser extent on the original manual tag data processing process requirements have increased, to a certain extent, the need for users to recreate the process.
- (4) Technical basis. RFID electronic tag system is a complete IT system, to maintain the normal operation of the system, it is necessary to have a strong system maintenance of the technical team long-term presence.
- (5) Standardization issues. 2007 National Bureau of standards began to develop our country RFID electronic tag application technology standards, but has not been released, so at this stage of the application of electronic tags have not been unified standards, can not form a consistent standard in different areas, different occasions. Although there are these problems of cost, technology and standards in use, but in order to improve management efficiency, RFID electronic tag application has been the general trend. At the same time with the continuous expansion of the application, its cost will fall to varying degrees, the adaptation of technology applications will also continue to improve, the unification of standards is just around the corner. So RFID electronic tag application prospects are very broad, on the application of the situation, there is no unsuccessful, only immature or not adaptable.
Design of RFID electronic tag antenna
The design goal of the electronic tag antenna is to transmit the maximum energy in and out of the tag chip, which requires careful design of the antenna and free space matching, as well as the antenna and tag chip matching. When the operating frequency increases to the microwave band, the matching problem between the antenna and the electronic tag chip becomes more severe. Has been, the development of electronic tag antenna is based on 50 or 75 input impedance, and in RFID applications, the chip input impedance may be arbitrary values, and it is difficult to test accurately in the working state, the lack of accurate parameters, the antenna design is difficult to achieve the best. The design of electronic tag antenna also faces many other difficulties, such as the corresponding small size requirements, low cost requirements, the shape and physical characteristics of the identified object requirements, electronic tag to labeling object distance requirements, labeling object dielectric constant requirements, metal surface reflection requirements, local structure on the radiation pattern requirements, etc., these will affect the characteristics of the electronic tag antenna, are electronic tag design Facing the problem. For the close range RFID system (such as 13.56MHz less than 10cm recognition system), the antenna and read-write generally integrated together; For the long range RFID system (such as UHF band greater than 3m recognition system), the antenna and read-write often take the separation type structure, and through the impedance matching coaxial cable will read-write and antenna connected to together. Read-write due to structure, installation and use of environment change variety, and read-write products towards miniaturization or even ultra-miniaturization development, make the read-write antenna design face new challenges. Reader antenna design requirements low profile, miniaturization and multi-band coverage. For the separated reader, also will involve the antenna array design problem, miniaturization brings low efficiency, low gain problem, etc., these are currently common concern research topic at home and abroad. At present has begun to study the read-write application intelligent beam scanning antenna array, read-write may in accordance with certain processing order, through the intelligent antenna enables the system to sense the antenna coverage area electronic label, increases the system coverage, enables the read-write to determine the target orientation, speed and direction information, has the space induction ability. RFID electron label antenna performance, depends to a large extent on the chip complex impedance, complex impedance is transformed with frequency, so the antenna size and operating frequency limit the maximum achievable gain and bandwidth, in order to obtain the best label performance, need to do compromise in the design to meet the design requirements. In the antenna design steps, the electronic tag reading range must be closely monitored, in the tag composition changes or different materials different frequency antenna for performance optimization, usually using adjustable antenna design to meet the design allowed deviation. When designing RFID antenna, first select the type of application, determine the demand parameters of the electronic tag antenna; then according to the parameters of the electronic tag antenna, determine the material used for the antenna, and determined the structure of the electronic tag antenna and the impedance after encapsulation; finally use the optimization, the impedance after encapsulation and antenna matching, comprehensive simulation of other parameters of the antenna, let the antenna meet the technical index, and use the network analyzer Test each index. Many antennas because of the use of complex environment, so that the analysis method of RFID antenna is also very complex, antenna usually use electromagnetic model and simulation tools to analyze. Antenna typical electromagnetic model analysis methods are finite element method FEM, moment method MOM and time domain finite difference method FDTD, etc. Simulation tool is very important for antenna design, is a fast and effective antenna design tool, and is now used more and more in antenna technology. Typical antenna design method, firstly, the antenna is modeled, then the model is simulated, in the simulation monitor the antenna range, antenna gain and antenna impedance, etc., and use the optimization method to further adjust the design, and finally the antenna is processed and measured until it meets the requirements.
Difference between RFID and NFC
Different operating frequency bands
NFC can be understood as a subset of RFID technology, which uses 13.56MHz frequency band, while RFID also includes other frequency bands. There are many working frequency bands of RFID, including 125kHz in low frequency band, 13.56MHz in high frequency band and 433.56mhz in UHF band MHz, 915MHz, and 2.4GHz in microwave band.
Different communication distance
NFC is called near-field communication, and the communication distance is really very close, no more than 0.1M. There are many kinds of RFID, and the recognizable distance is also different. Like RFID access control card, the identification distance is about the same as NFC. However, for the application scenario of etc, the recognition distance is required to be relatively long. The identification distance of long-distance RFID can reach tens of meters or even hundreds of meters.
Different application scenarios
Whether active or passive, RFID is mainly used to identify objects. RFID technology is widely used in logistics, transportation and storage to track goods. NFC chip has higher integration, including card reader and label. In addition, the two-way communication capability of NFC has been strengthened. In other words, NFC can not only be used as a tag to identify, but also as a two-way communication method for data exchange.
Radio frequency tag generally refers to radio frequency identification technology. Its principle is non-contact data communication between reader and tag to achieve the purpose of identification. RFID is widely used. Typical applications include animal chip, automobile chip anti-theft device, access control, parking lot control, production line automation and material management. The electronic tag is composed of transceiver antenna, AC / DC circuit, demodulation circuit, logic control circuit, memory and modulation circuit. Bar code is a graphic identifier that arranges multiple black bars and blanks with different widths according to certain coding rules to express a group of information. Common bar codes consist of black bars and white bars with very different reflectivity Bar code can mark many information such as the country of production, manufacturer, commodity name, production date, book classification number, starting and ending place, category and date of mail, so it is widely used in many fields such as commodity circulation, book management, postal management, banking system and so on. Conceptually, the two are very similar. This is also what some readers don’t understand. The purpose of both is to quickly and accurately confirm the tracking target object. The main differences between the two are as follows: 1. Is it “visible” The biggest difference between the two is that the barcode is a “visual technology”. The scanner works under the guidance of people and can only receive the barcode within its field of vision. In contrast, RFID does not require the target to be seen. RF tags can be read as long as they are within the scope of the receiver. Therefore, if the bar code is scratched, contaminated or falls off, the scanner cannot recognize the target. Bar codes can only identify producers and products, not specific commodities. The bar codes pasted on the packaging of all the same products are the same, and it is impossible to identify which products expire first. 2. Is there the ability to write information or update memory The bar code cannot be changed after printing. What information is scanned is what information. The information contained in the RF tag can be updated, modified and used for many times. 3. The two costs are different In terms of cost, RF tags are much more expensive than bar codes. The cost of barcode is the cost of barcode paper and ink. The price of active RF tag with memory chip is more than $2, and the cost of passive RF tag is more than $1. However, the price of a label without a built-in chip is only a few cents. It can be used when the data information requirements are not so high. At the same time, it also has the anti-counterfeiting function of anti-counterfeiting technology products that bar codes do not have. At present, the acceptance of bar code is higher all over the world, there is a perfect standard system, and RF technology is only limited to a limited market share.
RFID devices designed to be implanted in living organisms (such as animals or humans) have special requirements. They need to be wrapped in a special shell that does not stimulate or react with inserted living tissue. The shell must also be transparent to the scanning RF beam of the activated chip. Some RFID suppliers have created biocompatible glass for these applications. A potential problem placed in organisms is that tiny RFID devices may move under the skin. This can be avoided by using special materials that actually allow the surrounding tissue to grow into and bond with the casing. Because the RF wave that activates the microchip containing the identification number is only useful within a few feet (or less), the RFID chip is usually inserted very close to the skin surface. The placement of the device is usually performed with a hypodermic needle. This insertion method also determines the shape and size of the device; Implantable RFID devices are usually the size and diameter of a grain of rice. In dogs, the device is usually implanted between the shoulder blades. RFID tags have been placed in cows; The discussion about implanting RFID devices in all cows is due to the recent panic about mad cow disease. Dog owners use RFID tags to identify their pets instead of tattoos (a more traditional method).
What is an RFID fragile tag
The traditional anti-counterfeiting technology generally uses printing anti-counterfeiting, and the anti-counterfeiting label can be copied and moved. Not only did it not play a role in anti-counterfeiting, but it was copied by bad businesses, and more and more fake products flowed into the market, forming a vicious circle. With the combination of RFID and anti-counterfeiting technology, counterfeit products in the domestic market have been further curbed. RFID fragile anti-counterfeiting technology is used. Its electronic tag has an embedded chip and is the world’s unique number or commodity code information. The code can only be recognized by authorized reading and writing equipment. The RFID fragile label adopts special fragile paper and anti transfer glue, and the tag antenna removes the pet layer to realize the effect that the RFID fragile label cannot be peeled normally after pasting, anti transfer and anti tear. After it is pasted on the article, the antenna will automatically break when it is uncovered. Therefore, it plays an anti-counterfeiting role. It is mainly used in the anti-counterfeiting and traceability fields such as precious articles, tobacco and wine. RFID fragile tag can effectively prevent heat transfer; The original double-sided antenna coil adopts high-precision aluminum etching, which ensures the consistency between products and improves the quality of labels compared with printed antenna labels and semi printed semi aluminum (copper) etching antenna labels; The distance between aluminum and aluminum in the label is relatively consistent and not easy to fracture, which ensures the relatively consistent resistivity in the label, making the label information transmission, reading and writing stable and fast. This also enables RFID fragile tags to work stably in harsh environments such as ultraviolet and high temperature; At the same time, RFID fragile tags are resistant to bending, not easy to damage and have a longer storage time. Combined with the current popular two-dimensional code anti-counterfeiting printing and other technologies to achieve multiple anti-counterfeiting and use, and truly realize the RFID anti-counterfeiting traceability that consumers can check.
Anti conflict technology of RFID electronic tag
Bit oriented anti-collision mechanism. High frequency chip iso14443a is an anti-collision mechanism based on the principle that the card has only a unique serial number. For example, M1 card, each card has and only has a unique 32-bit binary serial number. How does the RFID reader detect conflicts between smart cards or electronic tags? The RFID card sends a command to the reader / writer using the subcarrier modulated Manchester code. The right half of the subcarrier modulation symbol represents the data “0”, and the left half of the subcarrier modulation symbol represents the data “1”. In case of conflict, the whole symbol has subcarrier modulation because the card returns “0” and “1” at the same time, and the reader / writer receives such a symbol, I knew there was a conflict. In this way, it can ensure that a smart card or electronic tag can be selected in case of conflict, and a card of the same type in the world can be selected after up to 32 anti conflict cycles. Slot oriented anti-collision mechanism. This anti-collision mechanism is used in ISO14443B. The timeslot here is actually a sequence number. The value range of this serial number is specified by the reader / writer. The possible ranges are 1-1, 1-2, 1-4, 1-8 and 1-16. When more than two cards enter the RF field at the same time, the RFID reader / writer sends a card call command to the RF field. The command specifies the range of time slot and allows the card to randomly select a number within this specified range as its own temporary identification number. Then, the reader / writer starts calling numbers from 1. If only one card selects this number when calling a number, this card will be selected to win. If there is no card response or more than one card response, continue to call down. If all the numbers in the value range have been called once and no card has been selected, let the card randomly select the temporary identification number again until a card is called. This method does not require the card to have a globally unique serial number, so there is no limit to the production quantity of smart cards, but in theory, there is a possibility that a card can never be selected. Anti collision mechanism based on bit and time slot Iso15693 uses an anti-collision mechanism combining bit and time slot. It is mainly realized in two aspects: one is that each smart card or RFID electronic tag has and only has a unique 7-byte serial number; the other is that the RFID reader uses the time slot number in the anti-collision work. The number here selects a part of the serial number of the smart card or electronic tag, not the random number. In addition, some special smart cards, such as TTF (tag talk first) cards, generally cannot prevent conflicts. Because this smart card will actively send the identification number after entering the RF field. If more than one smart card enters the RF field at the same time, it will not read the card. This smart card can only avoid conflicts manually.
How to cancel RFID tag?
How to disable RFID tags depends on the type of tag. If it is a passive UHF RFID tag based on electronic product code standard, the tag itself has cancellation function. If you know its security code, just send the security code to the label to disable it. If you do not know, or if it is a passive high-frequency or low-frequency tag, you need to interfere with it with current. There is a simple way to rub the carpet with your feet and use the static electricity from your fingertips to interfere with it. But if you want to make sure everything is safe, you can put the label directly into the microwave oven, or cut off one end of the old extension wire, peel off the peripheral insulators at both ends, make them touch the socket, and touch both ends with the chip or antenna, but be careful not to electrify yourself or burn down the house. If the tag is active, just remove the battery. Overloading the circuit can also destroy the active label.
What is an electronic label inlay card
Inlay is a special term in the RFID industry. It refers to a pre laminated product composed of multi-layer PVC or other materials containing chips and coils. Different types of RFID tags can be made through different forms of packaging. Inlay can be understood as an unpackaged semi-finished product of RFID tag.
- Inlay is divided into dry inlay and wet inlay;
- Dry inlay does not contain back glue, and its structure is antenna + chip + chip package;
- Wet inlay contains back glue, which can be directly pasted on articles. The structure is antenna + chip + chip packaging + surface paper + bottom paper;
- The electronic label inlay is actually a semi-finished product composed of antenna, pet or PVC, glue and wafer. Its antenna process adopts two processing methods: Aluminum etching and conductive silver paste printing. Electronic tag inlay is also known as the middle material of RFID tag. The middle material becomes an electronic label after being encapsulated by various substrates (such as paper, PVC, pet, etc.).
Source: China RFID Tags Manufacturer – Actility Technologies Company Limited (www.tractility.com) Actility provides powerful security solutions for retail store management to prevent asset and property losses, improve transaction security, and provide intelligent analysis. We produce AM/EM/RFID systems, EAS tags, EAS soft labels, EAS safer, lanyards, detachers and all kinds EAS accessories products. Infrared people counter and camera people counter is available. If you want to have more information about the article or you want to share your opinion with us, contact us at [email protected]
Please notice that you might be interested in the other technical articles we’ve published:
What is the difference between RFID tag and barcode?
RFID tags can be read through packaging and / or a certain distance, and barcodes need to be scanned. RFID tags can encode information multiple times, and bar codes can only be printed once. In general, RFID tags provide more flexibility and specificity for tracking individual items.
What is the difference between UPC and EPC?
UPC is the acronym of general product code. UPC is used to distinguish categories, while EPC tracks and identifies individual objects. EPC is the acronym of electronic product code.
What does UHF mean?
UHF is the abbreviation of UHF. It refers to the frequency at which RFID readers work and read RFID tags. UHF RFID tags can run over longer distances and transmit data faster.
What does EPC mean?
EPC is the acronym of electronic product code. This is specific to a single object, so it is usually used to distinguish the same items.