The 1 00 face of the1.tag is parallel to the antenna, so the reading effect is the best.
2. Ordinary labels cannot be directly attached to glass, liquid, human body and metal surfaces, which will cause frequency deviation of labels and seriously affect the reading effect.
3. If the RFID reader uses a linearly polarized antenna, the antenna of the tag should be in the same polarization direction as the antenna of the reader, and the reading effect is good.
4. when 4. UHF electronic tag inventory, reading EPC number, can be modified, but the version can be set with a write protection password, and can not be modified again without a password.
5. Unique number 5. UHF electronic tag is TID number, which is unique in the world and cannot be modified by default.
hope this helps
2. Common sense of active RFID
Active electronic tags can be divided into 433MHz, 900MHz and 2.45GHz according to their working frequencies.
According to the communication mode, it can be divided into one-way tag and two-way tag.
Active readers can be divided into card cards, wrist cards, seal cards, key cards, etc. Generally speaking, active readers can be divided into serial port type, network port type, CAN bus type and so on.
According to the forms of active readers, they can be divided into fixed readers, handheld readers and antenna readers.
It can also be divided according to the function of the reader. 1) operating frequency band
2) Reading distance of readers/authors
3) Anti-collision performance (number of tags read by readers at the same time)
4) reader sensitivity
5) tag storage capacity
6) Battery life, transmitting power and receiving sensitivity of the tag.
7) Label size, shape and protection (waterproof, dustproof, anticorrosive and explosion-proof) grade.
8) Anti-interference ability (whether it works normally under the interference of the same frequency signal)
9) Stability (tag missing rate)
10) security (encryption mode)
1 1) Extensibility (whether it supports RSSI, TDOA and other algorithm positioning and sensor combination) The basic working principle of RFID technology is not complicated. After the tag enters the magnetic field, it actively sends out a signal with a certain frequency, and the reader reads and decodes the information and sends it to the central information system for relevant data processing.
Generally speaking, there are two communication modes of active RFID:
1) Simplex: a working mode that can only send information in one direction between two points, generally corresponding to a one-way label;
2) Half-duplex: A working mode in which information can be sent in both directions between two points, but not at the same time. Usually corresponds to a two-way tag or a dual-frequency tag. 1) tag transmission power;
2) The tag is matched with the antennas at both ends of the reader;
3) that receive sensitivity of the reader;
4) working environment; 1) improve the tag transmission power;
2) Choose a reader antenna with high gain and good receiving effect;
3) Choose a good use environment;
4) improve the receiving sensitivity of the reader 1) increase the battery capacity;
2) extending the time interval of tag emission;
3) reducing the transmitting power of the tag;
The main solution is to equip a high-capacity battery with excellent performance and small size. 1) When the battery is low-voltage, the low-voltage alarm position of the tag information will be given by the upper computer after receiving the alarm information;
2) When the battery voltage is low, the low-voltage battery lamp on the label flashes and gives an alarm message; 1) reasonably control the use ratio of tags and readers;
2) reducing the time interval of tag emission;
3) Good anti-collision algorithm; Inductive tag refers to the tag that uses RFID to realize identification and acquisition. A plurality of sensors are arranged outside the tag to collect data, and then the data is transmitted to the upper computer through RFID communication.
3. Knowledge about electronic labels
Electronic tag RFID is also called radio frequency tag and radio frequency identification.
It is a non-contact automatic identification technology, which identifies the target object through radio frequency signals and obtains relevant data without manual intervention. As a wireless version of bar code, RFID technology has the advantages of waterproof, antimagnetic, high temperature resistance, long service life, long reading distance, encrypted data on the label, larger storage capacity, and freely changeable stored information. Electronic Tag is also called smart tag, which is tag or Smart Label in English.
Its core is a small memory chip using RFID technology. Let's talk about it
Description of electronic label 1 Characteristic data storage of electronic tags: Compared with traditional tags, it has a larger capacity (1bit-1024 bit), and the data can be updated and read and written at any time. Reading and writing speed: Compared with bar code, it does not need linear alignment scanning, so it is faster to read and write, and can realize multi-target recognition and action recognition.
Easy to use: small size, easy to package, can be embedded in the product. Security: special chip, unique serial number, difficult to copy.
Durable: no mechanical failure, long service life and resistance to harsh environment. 2. Technical Principle A typical RFID system includes an electronic tag, a reading/writing device and a data exchange and management system.
Electronic tag, also known as radio frequency card, has the ability of intelligent reading and writing and encrypted communication. The reader consists of a wireless transceiver module, an antenna, a control module and an interface circuit.
There is no battery in the electronic tag, and the working energy of the electronic tag is provided by the radio frequency pulse sent by the reader. The electronic tag receives the RF pulse, rectifies it and charges the capacitor.
The capacitor voltage is stabilized to the operating voltage. The data demodulation section demodulates data from the received RF pulse and sends it to the control logic.
The control logic accepts instructions to complete storage, data transmission or other operations. EEPROM is used to store the ID number and other user data of electronic tags.
There is also an active RFID system, powered by batteries, which can work in a higher frequency band, have a longer recognition distance and have a higher communication rate with readers. RFID systems are divided into low frequency, intermediate frequency and high frequency systems according to different working frequencies.
Generally, the low frequency system works at 100k~500kHz, and the intermediate frequency system works at 10MHz~ 15MHz, which is mainly suitable for applications with short identification distance and low cost. The high frequency system can reach 850~950MHz and 2.4~5GHz microwave bands, which is suitable for occasions with long recognition distance and high data reading and writing rate. 3. Comparison of identification technologies As far as barcode, magnetic card, ic card and RFID are concerned, they all have their own characteristics and are suitable for application.
The following table lists the characteristics and differences of several identification technologies. 4. Compared with bar codes, electronic tags can be read and written easily even if they are invisible; Able to work in various complex environments; Can be easily embedded or attached to different products in different forms; Longer reading and writing distance, three-dimensional reading and writing mode; Greater storage capacity; With key protection, it is more secure and difficult to forge.
Application of electronic tag As a data carrier, electronic tag can play the role of identity identification, item tracking and information collection. In foreign countries, electronic tags have been used in a wide range of fields.
The RFID system consisting of electronic tag, reader, antenna and application software is directly connected with the corresponding management information system. Everything can be tracked accurately. This comprehensive information management system can bring many benefits to customers, including real-time data collection, secure data access channel, and all product information can be obtained offline.
Abroad, RFID technology has been widely used in many fields, such as industrial automation and commercial automation. The scope of application includes: 1, anti-counterfeiting (abbreviated as electronic version below). Through scanning, detailed logistics records are generated.
(1) The electronic label for production line management can conveniently and accurately record the process information and process operation information on the production line, and meet the requirements of flexible production. The record of workers' job number, time, operation and quality inspection results can completely realize the traceability of production.
It can also avoid errors caused by handwriting and reading information in production environment. (2) The warehouse management RFID system is applied to the intelligent warehouse goods management, which effectively solves the information management of warehouse goods.
For large storage bases, the management center can know the location and storage of goods in real time, which is of great significance for improving storage efficiency, feeding back product information and guiding production. It not only increases the number of goods handled in one day, but also can monitor all the information of goods.
Among them, there are various application forms, which can be labeled on the goods and read and written by readers on forklift trucks and readers in corresponding positions in warehouses; You can also combine bar codes with electronic labels. (3) Sales channel management It is a strong demand of many enterprises to establish strict and orderly channels and efficiently manage invoicing.
In the production process, products are embedded in electronic labels, which contain unique product numbers. Manufacturers can monitor the flow of products with identifiers, and wholesalers and retailers can identify the legitimacy of products with readers provided by manufacturers. 3, valuables management can also be used for cameras, camcorders, portable computers, CD walkman, jewelry, etc.
Anti-theft, settlement and after-sales protection of valuables. Its anti-theft function belongs to Electronic Commodity Anti-theft System (EAS).
Labels can be attached to or embedded in the packaging of articles. A special shelf scanner will scan goods in real time and get real-time inventory records.
If the goods are taken from the price, the system will verify whether this behavior is legal, and if the goods are taken illegally, the system will call the police. When the bill leaves the warehouse, all different kinds of items can be scanned by the scanner at one time, and the anti-theft function is released at the same time when the sales slip is generated at the cashier.
In this way, when customers leave with shopping items, the alarm will not sound. When the customer pays the bill, the cashier will write down the date of sale on the label, so that the goods purchased by the customer can also be guaranteed and promised accordingly.
4. Book management, rental product management By attaching electronic labels to books, it is convenient to receive book information, and it is not necessary to move books when sorting books, which can improve work efficiency and avoid work mistakes. 5. Others, such as logistics, car anti-theft and air parcel management.
4. where can I 4. Use RFID tags?
In logistics supply chain management, RFID tags can be used to track materials and products in the whole supply chain process.
From supplier supply to production, warehousing, distribution, transportation and sales. Production enterprises, in manufacturing units (such as workshops), require to ensure that the production process is orderly and correct; In the storage unit, raw materials and products (semi-finished products and finished products) are required to be accurately classified and placed.
In order to ensure the quality of products, raw materials and semi-finished products must be processed, packaged, labeled, placed and stored in the warehouse, and the finished products will be produced through the manufacturing process in the workshop and then returned to the warehouse. In each process, it is required to label the production and storage units of materials to avoid the loss and error of product information.
Therefore, it is necessary to use modern positioning and communication technology to establish a full-time, all-airspace, all-weather logistics tracking and communication information system (LTCIS) to meet the requirements and development of modern logistics supply chain.
5. What is 5? What is RFID and its security knowledge?
RFID radio frequency identification is a non-contact automatic identification technology, which can automatically identify the target object and obtain relevant data through radio frequency signals, and can work in various harsh environments without manual intervention. RFID technology can identify high-speed moving objects and multiple tags at the same time, which is quick and convenient to operate.
RFID is a simple wireless system with only two basic devices, which is used to control, detect and track objects. The system consists of an interrogator (or reader) and many transponders (or tags).
Classification of RFID
According to different application frequencies, RFID can be divided into low frequency (LF), high frequency (HF), ultra-high frequency (UHF) and microwave (MW), and the corresponding representative frequencies are: low frequency1below 35 kHz, high frequency 13.56MHz, ultra-high frequency 860M~960MHz, microwave 2.4g and 5.8g respectively.
According to the energy supply mode, RFID can be divided into passive RFID, active RFID and semi-active RFID. Passive RFID has short reading and writing distance and low price; Active RFID can provide a longer reading and writing distance.
6.RFID tags
There are many kinds of RFID tags. I wonder which frequency band the landlord wants to use?
RFID tags are mainly divided into two categories: active (battery-powered) tags and passive (unpowered) tags.
According to the working frequency band, there are 13.56 MHz, 433 MHz, 915mhz, 2.45 GHz and so on. , corresponding to low frequency, high frequency, ultra-high frequency and microwave respectively, and the tags of each frequency band also have their own corresponding protocols, such as ISO 15693, and 65438 corresponds to 65438. 6C protocol, but there is no unified protocol for microwave cutoff (2.45G) at present, and most of them are internal protocols of manufacturers. At present, 13.56m and 9 15m are mostly passive tags, while 2.45g and 433m have active tags. The landlord must first know what he really needs.
Basically, the lower the working frequency band, the closer the recognition distance.
Active tags have short service life and passive tags have long service life.
7. How to choose an appropriate RFID tag?
The application of RFID electronic tag mainly meets one or more of the following requirements: (1) the traceability of article information; (2) Requirements of high precision and high safety; (3) the requirement of uniqueness and unforgeability; (4) need to deal with a large number of projects quickly; (5) Monitor the demand of goods in real time.
Visible application market is not limited to the above, as long as the system has the above requirements, electronic tags can be applied. So how to choose a suitable RFID tag? Let's talk about it
Why do you need to customize RFID technology as one of the main means of automatic data acquisition at present? Electronic tag is an indispensable part of RFID system, but in most cases, the universality of electronic tag is not strong, but different RFID electronic tags can be selected according to the needs of the scene. For example, in terms of frequency bands, it can be divided into LF, HF, UHF, 2.4G and 5.8G Different frequency bands have their own advantages and disadvantages-low-frequency products have good penetration, but the data transmission rate is limited, which can be applied to animal management; High frequency (HF) is usually suitable for payment and identification due to its reading distance and protocol limitations. Passive ultra-high frequency (UHF) can be read in a long distance, its biggest feature is that it can be read in batches at one time, but it is easily disturbed by the environment, especially metals and liquids, and it is mainly used in clothing retail and logistics storage. 2.4G and 5.8G active products have stable signal, large data transmission capacity and long reading distance, but the battery life is poor and the price is high, which is the shortcoming of application.
Products in the same frequency band have great differences in packaging forms and installation methods due to different use environments. Taking HF as an example, it is often used for payment and identity management in the form of PVC cards. When used for safety traceability, fragile paper or coated paper can be selected. The products in the same frequency band have the same application, but also show some differences because of the particularity of the problems encountered by customers.
For example, when tracing milk powder with HF fragile label, if the surface of milk powder can is plastic, it can be pasted directly. If it is made of metal, it is necessary to consider adding a layer of absorbing material. Generally speaking, the different requirements of frequency band characteristics, application scenarios, performance indicators and installation methods of RFID electronic tags affect the standardization of RFID, so the customized development of RFID electronic tags is the key factor to determine the success of RFID system application.
The working principle of RFID How to customize RFID tags and develop customized RFID tags is a systematic project. According to the author's experience, it needs to go through six stages: demand assessment, preliminary selection, cost assessment, sample development, scene measurement and selection optimization. The time spent varies according to the complexity of the project requirements, ranging from half a month to more than three months. 1 needs assessment needs assessment is the most critical step. We need to evaluate whether RFID technology is needed according to the user's application scenario.
Not all applications are suitable for RFID technology, such as the traceability of many primary agricultural and industrial products-cabbage, grapefruit, steel, pipe fittings and so on. These products can't afford to buy because of their low value, and the application effect will be affected by the interference of items in the application process. Therefore, lower-cost bar code technology is often used to solve the problem.
So when do you choose RFID technology? Taking airport baggage sorting as an example, firstly, in terms of cost, the aviation industry has a large volume, high service value, very high requirements for efficiency and high tolerance for efficiency costs; Secondly, technically, the bar code identification of luggage cannot be fixed in place. If the bar code technology is used, it is difficult to read and process in batches, and it is often necessary to manually assist one-to-one reading, which is inefficient and costly. This has formed a strong demand for RFID technology-UHF technology can greatly improve the luggage sorting speed at a relatively low cost, while ensuring accuracy.
That is, demand assessment is to confirm whether RFID can meet the technical and cost requirements according to the user's application scenarios, and if so, adopt this technology. Preliminary selection of RFID tags for luggage sorting 2 After it is clear that RFID technology can solve the "pain point" of demand, the key to the next step is the selection of RFID tags.
According to the demand assessment results, the frequency band, product size, chip type, packaging form and installation method of electronic tags are selected. Taking the selection of a fragile product label as an example, the process is introduced: a customer needs a label for the outer packaging carton of high-end consumer products, with the purpose of anti-counterfeiting and traceability.
In order to facilitate consumer verification, we suggest adopting high frequency 14443A protocol; The paper box is square, and the folding position has certain elasticity. We suggest packing with coated paper, which is both tear-proof and elastic. In order to facilitate the installation, we use glue.
In chip selection, customers proposed to adopt the chips they provided. For this reason, we re-developed a line type according to the chip data; Considering that the folding position requires a slightly longer label, which will increase the cost if the size is too large, we recommend a rectangular label with appropriate size to our customers. 3 After the initial selection of cost evaluation meets the customer's requirements, the cost evaluation is conducted according to the results.
The main factors affecting the cost are chip type, packaging form, product size and data requirements. First, chips can be imported or made in China according to different needs. Generally speaking, the price of imported chips will be higher. The higher the storage capacity, the higher the price of chips with more functions, such as encryption function, TD function and dual-frequency function. Secondly, packaging, the more complex the packaging structure, the more difficult the packaging and the higher the cost.
Size is also an influencing factor. The larger the size, the higher the price. But in the field of micro-labels, the smaller the size, the higher the price, because the processing is more difficult. Data requirements mainly involve surface coding, writing data, extracting data and data association, each of which will increase the cost.
Because of these factors, we usually provide 3~4 sets of schemes for customers' reference, and choose the best scheme for sample development. 4 sample development in the process of sample development, the most important thing is not the amount of research and development expenses, but the length of research and development cycle.
The shorter the time spent in this part of the work, the greater the contingency space in the later stage of the project, and the higher the success rate of the project. Sample study.