Wireless tag (RFID): it's not easy to say I love you.
this compilation report: those words about the RF identification device were put forward by J. Michael Wallace, director of packaging process development, boss products Div. of Abbott laboratory, and nutrition manufacturers including assure and SimilacWallace spoke at a World Symposium on June 8, entitled "RFID: the experience of a packer", which was co sponsored by the packaging professional association and the world packaging magazine Abbott began to study RFID in 1998, and was also studying an alternative electronic document viewing system at that time. Two years later, the company joined MIT's automatic identification center, which includes its largest customers - Wal Mart, CVs and target, as well as its competitors, such as Unilever Wallace said, "we are very interested in discovering what others have learned about RFID, but we still don't understand it. We find that RFID has quite a lot of benefits and potential benefits."
the company is currently conducting three flight experiments. These experimental devices were launched at the end of 2003, two of which are pharmaceutical products and one is nutritional products. According to Wallace, these contain very little. The RFID system will also be effective after being transferred from the flight route to the plants. The company expects to launch its first labeled products in 2005
abbott will use MATRICS' labels and card readers, and cooperate with his corrugated paper supplier to produce labels using RFID trademarks. However, he could not provide details. Wallace said, "most corrugated paper suppliers are seriously considering RFID."
"it is impossible to do this project alone, because there are too many technical problems," Wallace said. He suggested calling on all consultants and decision makers to work together to solve hardware, software and some comprehensive problems
he also said, "take RFID out of the laboratory and use it on plants, check the emission of RF devices, and evaluate the performance of tags and card readers."
now for Abbott, his biggest challenge is how to make RFID cooperate with the company's current IT system, which has gradually matured over the years. Wallace said, "this is not an easy thing."
wallace decided to reach RFID in five steps: research, test, experiment, measurement and tools. "The most valuable thing is the final result," he said
related links: introduction to RFID technology
rfid is the abbreviation of "radio frequency identification". Radio frequency technology uses radio waves to read and write recording media. The distance of RFID can reach tens of centimeters to several meters, and thousands of bytes of information can be input according to the way of reading and writing. At the same time, it also has high confidentiality. The application fields of RFID Technology: material tracking, vehicle and shelf identification and other occasions requiring non-contact data acquisition and exchange, especially those requiring frequent changes in data content. For example, the main technology used in Hong Kong's automatic vehicle identification system, easy connect, is RF technology. At present, about 80000 vehicles in Hong Kong have been equipped with electronic tags. When vehicles equipped with electronic tags pass through special tunnels, parking lots or highway crossings equipped with RF scanners, they do not need to stop and pay fees, which greatly improves the driving speed and efficiency. Radio frequency technology has also been widely used in the identification and automatic management of other items
at present, RFID is the most popular technology in the field of AIDC. Although this technology has existed and developed for many years, it can be quickly and practically applied only after summarizing and planning a technical standard from many invention technologies in this field. ISO and aim (Auto-ID manufacturers) are working in this field. I believe that RFID will develop rapidly in the near future
1. Composition of RFID system
rfid system in the specific application process, the composition of the system will be different according to different application purposes and application environments, but from the working principle of RFID system, the system is generally composed of signal transmitter, signal receiver and transmitting and receiving antenna. It is explained below:
1) signal transmitter
in RFID system, signal transmitter will exist in different forms for different application purposes, and the typical form is tag. The label is equivalent to the bar code symbol in bar code technology, which is used to store the information that needs to be identified and transmitted. In addition, unlike bar code, the label must be able to automatically or under the action of external forces, and actively transmit the stored information. Labels are generally low-power integrated circuits with coils, antennas, memory and control systems. The typical label structure is shown in the figure above: according to different classification standards, labels have many different classifications
(1). Active tags, passive tags
in practical applications, the tag must be powered to work, although its power consumption is very low (generally one millionth of a milliwatt level). Labels can be divided into active labels and passive labels according to different ways of obtaining electric energy. The active tag is powered by its own battery, which has sufficient power, high reliability and long signal transmission distance. In addition, the active tag can limit the use time or times of the tag by designing the different service life of the battery. It can be used where the data transmission volume needs to be limited or the use of data is limited. For example, the tag can only be read and written a limited number of times in a year. The main disadvantage of active tags is that the service life of tags is limited, and with the consumption of battery power in tags, the distance of data transmission will be smaller and smaller, affecting the normal work of the system
there is no battery inside the passive label, and it can work normally only by providing energy from the outside. The typical devices that generate electric energy for passive tags are antennas and coils. When the tag enters the working area of the system, the antenna receives a specific electromagnetic wave, and the coil will generate induced current to supply power to the tag through the rectifier circuit. Passive tags have a permanent service life, and are often used where tag information needs to be read and written daily or frequently many times. Moreover, passive tags support long-term data transmission and permanent data storage. The disadvantage of passive tags is that the distance of data transmission is smaller than that of active tags. Because the passive tag relies on external electromagnetic induction to supply power, its power is relatively weak, and the distance and signal strength of data transmission are limited. Only a highly sensitive signal receiver (Reader) can reliably read it
(2) read only labels and readable and writable labels
labels can be divided into read-only labels and readable and writable labels according to the different types of internal memory. Inside the read-only tag, there are only read only memory (ROM) and random access memory (RAM). ROM is used to store the operating system description of the transmitter and the data with high security requirements. It completes the internal operation control functions with the internal processor or logic processing unit, such as response delay time control, data flow control, power switch control, etc. In addition, the ROM of the read-only label also stores the label identification information. These information can be written into ROM by the manufacturer during the label manufacturing process, or the user can write special coding information according to the specific application purpose when the label is used. This kind of information can simply represent "0" or "1" in binary, or it can contain complex and rich information like two-dimensional bar code. However, such information can only be written once and read many times. The R in the read-only tag is extremely strong, and the AM is used to store the data temporarily generated in the tag reaction and data transmission process. In addition, in addition to ROM and ROM, there is usually buffer memory in the read-only tag, which is used to temporarily store the information waiting for the antenna to send after modulation
in addition to ROM, ram and buffer memory, the memory inside the readable and writable label also has inactive programmable memory. In addition to the function of storing data, this memory also "compresses" the polymer matrix between the layers of carbon fiber composites, which has the function of allowing multiple writes of data under appropriate conditions. There are many kinds of inactive programmable memory, and EEPROM (electrically erasable programmable read only memory) is a common one. This kind of memory can erase the original data and rewrite the data when powered on
(3) identification tag and portable data file
according to the different storage capacity of the memory data in the tag, the tag can be divided into identification tag and portable data file for identification purposes only. For identification tags, a number or multiple alphanumeric strings are stored in the tag for identification purposes or as a key to the database in the information management system. In bar code technology, the number of standard code system, such as ean/upc code, or mixed code, or the number compiled by the label user according to a special method, can be stored in the identification label. What is stored in the identification tag is only the identification number, which is used to identify specific identification items, such as people, objects and places. The detailed specific information about the identified items can only be found in the database connected to the system
as the name suggests, portable data file means that the data stored in the tag is large enough to be regarded as a data file. This kind of label is generally user programmable. In addition to storing the identification code, the label also stores a large number of other relevant information of the identified items, such as packaging instructions, process instructions and so on. In practical application, all the information about the identified item is stored in the tag. Reading the tag can get all the information about the identified item without connecting to the database for information reading. In addition, with the improvement of label storage capacity, it can provide the ability to organize data. In the process of reading labels, the reading of data can be controlled according to specific application purposes, especially for bridge cables with steel below 10mm, the part of data read out is different under different circumstances
2) signal receiver
in RFID system, signal receiver is generally called reader. The complexity of readers is significantly different according to the types of tags supported and the functions completed. The basic function of the reader is to provide a way to transmit data with the tag. In addition, the reader also provides quite complex signal state control, parity error verification and correction functions. In addition to storing the information to be transmitted, the tag must also contain some additional information, such as error verification information. As an important part of the instrument, the identification data information and the fixture of the additional tensile testing machine are compiled together according to a certain structure and sent out in a specific order. The reader controls the sending of data flow by receiving additional information. Once the information arriving at the reader is correctly received and interpreted, the reader determines whether the transmitter needs to resend the transmitted signal or knows that the transmitter stops sending signals through a specific algorithm, which is "command response protocol"