Introduction to the operating environment and interface methods of RFID application systems

RFID technology is a key technology for the development of the Internet of Things, and its application market will surely expand with the development of the Internet of Things. This article mainly introduces the operating environment and interface methods of the radio frequency identification application system in detail. Follow the editor to learn more about it.

Introduction to radio frequency identification application system

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

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

Application of RFID technology

1. In the Retail Industry, the application of barcode technology enables tens of thousands of product types, prices, origins, batches, shelves, inventory, etc.

2. The use of automatic vehicle identification technology allows vehicles to queue up for customs clearance at road bridges, parking lots and other toll collection places, reducing time waste, thus greatly improving transportation efficiency and the capacity of transportation facilities;

3. In the automated production line, all aspects of the entire product production process are placed under strict monitoring and management;

4. In harsh environments such as dust, pollution, cold, and heat, the application of long-range radio frequency identification technology improves the inconvenience of truck drivers having to get out of the car to go through the 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 line, providing real-time and reliable information for vehicle dispatching and full operation management.

Introduction to the operating environment and interface methods of radio frequency identification application systems

The operating environment of radio frequency identification application system

A complete radio frequency identification application system should include readers, electronic tags, computer networks and other equipment. Considering issues such as data reading, processing, and transmission, the installation of the reader antenna and the distance of 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.

Introduction to the operating environment and interface methods of radio frequency identification application systems

Interface method of radio frequency identification application system

(1)RJ45

RF45 and Category 5 lines are used together in Ethernet networks. The 8 lines are divided into 4 groups, which are composed of 8 single colors or white color lines: red and white, red, green and white, green, blue and white, blue, brown and white, and brown. There are two RJ45 connection methods, namely T-568A and T-568B. The only difference between the two connection methods is the different line sequence.

RJ45 transmits signals farther and uses the TCP/IP protocol.

(2)RS-232

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

RS-232 is a comprehensive serial transmission interface developed by the Federation of Electronic Industries and is used to connect data terminal equipment to data communication equipment. RS-232 specifies the types of wires and connectors, the connection methods 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 using stable lines, which has stronger anti-interference ability than RS-232. RS-422 data transmission speed When other conditions are the same, the identification distance of the low-frequency system is the shortest, followed by the medium- and high-frequency system, and the microwave system. The identification distance of the microwave system is the farthest. As long as the frequency of the reader changes, the operating frequency of the system will change accordingly.

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

The packaging form of electronic tags is also one of the reasons that affects the recognition distance of the system. The larger the antenna of the electronic tag is, that is, the greater the magnetic flux acquired by the electronic tag passing through the active area of the reader, and the greater the energy Stored.

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

Usually in RFID applications, choosing the appropriate antenna can meet the needs of long-distance reading and writing. For example, the FastTrack conveyor belt antenna is designed to be installed on a conveyor belt between rollers, and the REID 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

For most data acquisition systems, speed is a very important factor. Due to the continuous shortening of product production cycles today, the time required to read and update RFID carriers is getting shorter and shorter.

①Read-only speed

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 and write distance, the carrier frequency between the carrier and the antenna, and the modulation technology of data transmission. The transmission rate varies depending on the type of product in the actual application.

② Passive read and write speed

The factors that determine the data transfer rate of a passive read-write REID system are the same as those of a read-only system. However, in addition to reading data from the carrier, you must also consider writing data to the carrier. The transmission rate varies depending on the product type in the actual application.

③Active read and write rate

The data transmission rate determinants of active read-write RFID systems are the same as passive systems. The difference is that passive systems need to activate the capacitor charging on the carrier to communicate. An important point is that a typical low-frequency read and write system may only operate at 100 bytes/s or 200 bytes/s. Thus, since there may be hundreds of bytes of data to be transferred at one site, the data transmission time will take several seconds, which may be longer than the entire machine operation. EMS has used several unique and proprietary technologies to design a low-frequency system that operates at higher speeds than most microwave systems.

Introduction to the operating environment and interface methods of radio frequency identification application systems

(4)Safety requirements

Security requirements generally refer to encryption and identity authentication. A planned RFID system should have a very accurate assessment of its security requirements in order to rule out from the outset various dangerous attacks that may arise during the application phase. To this end, it is necessary to analyze various security vulnerabilities existing in the system, the possibility of attacks, etc.

(5)Storage capacity

The storage capacity of the data carrier is different, and the price of the system is also different. 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-encoding read-only data carriers should be selected. If you want to write information into the electronic tag, you need to use an electronic tag with EEPROM or RAM storage technology, and the system cost will increase.

There is a basic rule in memory-based systems, that is, the storage capacity is always insufficient. There is no doubt that expanding system storage capacity will naturally expand application areas. The storage capacity of the read-only carrier is 20 bits, and the storage capacity of the active read-write carrier ranges from 64B to 32KB, which means that several pages of text can be stored in the read-write carrier, which is enough to load the manifest and test data , and allow system expansion. The storage space of passive read-write carriers ranges 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 REID system should be able to interface directly with a personal computer, programmable logic controller or industrial network interface module (fieldbus), thereby reducing installation costs. Connectivity enables RFID technology to provide flexible functionality and easy integration 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 also needs to be considered. This is related to the reading performance of the reader and the moving speed of the electronic tag, etc.

(8) Packaging form of electronic label

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 needs to be considered. The packaging form of electronic tags not only affects the working performance of the system, but also affects the safety performance and appearance of the system.

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