Introduction to the operating environment and interface mode of RFID application system

灞波儿奔

Introduction to the operating environment and interface mode of RFID application system [Copy link]

As a key technology for the development of the Internet of Things, the application market of RFID technology will surely expand with the development of the Internet of Things. This article mainly introduces the operating environment and interface mode of the radio frequency identification application system in detail. Let's follow the editor to learn more about it.

　　Introduction to RFID Application System

　　RFID is a non-contact automatic identification technology that automatically identifies the target object and obtains relevant data through radio frequency signals. The identification work does not require human intervention and can work in various harsh environments. RFID technology can identify high-speed moving objects and can identify multiple tags at the same time. The operation is quick and convenient.

　　Short-range RF products are not afraid of harsh environments such as oil stains and dust pollution, and can replace barcodes in such environments, such as tracking objects on factory assembly lines. Long-range RF products are mostly used in transportation, with an identification distance of up to tens of meters, such as automatic toll collection or vehicle identification.

　　Application of RFID Technology

　　1. In the retail industry, the use of barcode technology enables tens of thousands of commodity types, prices, origins, batches, shelves, inventories, etc.

　　2. The use of automatic vehicle identification technology avoids the phenomenon of vehicles queuing for customs clearance at toll places such as roads, bridges, and parking lots, reducing time waste, thereby greatly improving transportation efficiency and the traffic capacity of transportation facilities;

　　3. On the automated production line, every link of the entire production process is under strict monitoring and management;

　　4. In harsh environments such as dust, pollution, cold and heat, the use of long-range RFID technology improves the inconvenience of truck drivers having to get off the vehicle to handle formalities;

　　5. In the operation management of buses, the automatic identification system accurately records the arrival and departure times of vehicles at various stations along the route, providing real-time and reliable information for vehicle scheduling and overall operation management.

　　

　　Operating environment of RFID application system

　　A complete RFID application system should include readers, electronic tags, computer networks, etc. Considering data reading, processing, transmission, etc., the installation of the reader antenna and the transmission distance should also be considered.

　　The operating environment of radio frequency identification technology is relatively loose. From the perspective of the operating environment of the application software system, any software based on any programming language can be run on any existing system.

　　Computer platform systems include Windows, Linux, UNIX and DOS platform systems.

　　

　　Interface mode of RFID application system

　　（1）RJ45

　　RF45 and Category 5 cables are used together in Ethernet networks. The 8 cables are divided into 4 groups, consisting of 8 single colors or white stripes: red and white, red, green and white, green, blue and white, blue, brown and white, and brown. There are two ways to connect RJ45, namely T-568A and T-568B. The only difference between the two methods is the line sequence.

　　RJ45 transmits signals over longer distances and uses the TCP/IP protocol.

　　（2）RS-232

　　RS-232 is a popular computer serial interface. Commonly used RS-232 interfaces include DB9 and DB25.

　　RS-232 is a widely used serial transmission interface developed by the Electronic Industry Association to connect data terminal equipment to data communication equipment. RS-232 specifies the type of wires and connectors, the connection method of the connectors, and the function, voltage, meaning and control process of each wire. RS-232 is compatible with ITU's V.24 and V.28.

　　（3）rs-485/' target='_blank'>RS-485／ RS-422

　　RS-422 is a full-duplex interface that uses a stable line and has a stronger anti-interference ability than RS-232. When other conditions of RS-422 data transmission speed are the same, the low-frequency system has the shortest recognition distance, followed by the medium-high frequency system and the microwave system. The microwave system has the longest recognition distance. As long as the frequency of the reader changes, the operating frequency of the system will change accordingly.

　　The effective identification distance of the RFID system is proportional to the RF transmission power of the reader. The greater the transmission power, the farther the identification distance. However, when the radiation generated by electromagnetic waves exceeds a certain range, it will have a harmful effect on the environment and human body. Therefore, certain power standards must be followed in terms of electromagnetic power.

　　The packaging form of the electronic tag is also one of the factors that affect the system's recognition distance. The larger the antenna of the electronic tag, that is, the greater the magnetic flux obtained by the electronic tag when it passes through the active area of the reader, the greater the stored energy.

　　The required working distance of the application project depends on many factors: the positioning accuracy of the electronic tag; the minimum distance between multiple electronic tags in actual application; and the moving speed of the electronic tag in the working area of the reader.

　　Usually in RFID applications, choosing the right antenna can meet the needs of long-distance reading and writing. For example, FastTrack conveyor belt antenna is designed to be installed on the conveyor belt between rollers, and the RFID carrier is installed on the bottom of the pallet or product to ensure that the carrier passes directly over the antenna.

　　(3) Data transmission rate

　　Speed is a very important factor for most data collection systems. As today's production cycles are constantly shortening, the time required to read and update RFID carriers is getting shorter and shorter.

　　① Read-only rate

　　The data transmission rate of the RFID read-only system depends on factors such as the length of the code, the carrier data transmission rate, the read/write distance, the carrier frequency between the carrier and the antenna, and the modulation technology of the data transmission. The transmission rate varies with the type of product in the actual application.

　　② Passive read and write speed

　　The data transmission rate of the passive read-write REID system is determined by the same factors as the read-only system, but in addition to considering reading data from the carrier, it is also necessary to consider writing data to the carrier. The transmission rate varies with the type of product in the actual application.

　　③ Active read and write speed

　　The data transmission rate of active read-write RFID systems is determined by the same factors as passive systems, except that passive systems need to activate the capacitor charging on the carrier to communicate. It is important to note that a typical low-frequency read-write system may only operate at a rate of 100 bytes/s or 200 bytes/s. In this way, since there may be hundreds of bytes of data to be transmitted at a site, the data transmission time will take several seconds, which may be longer than the entire mechanical operation time. EMS has designed a low-frequency system with a higher rate than most microwave systems by using several unique and proprietary technologies.

　　

　　(4) Safety requirements

　　Security requirements generally refer to encryption and identity authentication. A planned RFID system should be evaluated very accurately in terms of its security requirements, so that all kinds of dangerous attacks that may occur during the application phase can be eliminated from the very beginning. To this end, it is necessary to analyze the various security vulnerabilities in the system and the possibility of attacks.

　　(5) Storage capacity

　　The system price varies with the size of the data carrier storage capacity. The price of the data carrier is mainly determined by the storage capacity of the electronic tag.

　　For price-sensitive applications with low on-site requirements, fixed-coded read-only data carriers should be selected. If information needs to be written into the electronic tag, an electronic tag with EEPROM or RAM storage technology is required, which will increase the system cost.

　　A basic rule of memory-based systems is that there is never enough storage capacity. Of course, expanding the system's storage capacity will naturally expand the application area. The storage capacity of read-only media is 20 bits, and the storage capacity of active read-write media ranges from 64B to 32KB, which means that several pages of text can be stored in a read-write medium, which is enough to load cargo lists and test data and allow system expansion. Passive read-write media have storage space ranging from 48B to 736B, and it has many features that active read-write systems do not have.

　　(6) Connectivity of RFID system

　　As a development branch of automation systems, RFID technology must be able to integrate existing and developing automation technologies. Importantly, the RFID system should be able to be directly connected to a personal computer, programmable logic controller or industrial network interface module (fieldbus) to reduce installation costs. Connectivity enables RFID technology to provide flexible functions and is easy to integrate into a wide range of industrial applications.

　　(7) Simultaneous reading of multiple electronic tags

　　Since the system may need to identify multiple electronic tags at the same time, the multi-tag readability provided by the reader must also be considered. This is related to the reader's reading performance, the moving speed of the electronic tags, etc.

　　(8) Packaging form of electronic tags

　　 For different working environments, the size and form of the electronic tag determine the installation and performance of the electronic tag. The packaging form of the electronic tag is also one of the parameters that need to be considered. The packaging form of the electronic tag not only affects the working performance of the system, but also affects the safety performance and aesthetics of the system.

　　 The evaluation of RFID system performance indicators is very complex. There are many factors that affect the overall performance of the RFID system, including product factors, market factors, and environmental factors.

　　

alan000345

Nice sharing.