Student and teacher information collection is a core part of the system of "home school and school communication", and it is the key to correctly identify how students should be admitted to school and send out safe short messages to parents accurately. System integrators are now widely used RFID rfid radio frequency identification technology. When students carry electronic cards through the school gate, the equipment placed around the school gate senses the information and reports it to the software end, thus completing the process of collecting information. At present, the rapid development of rfid technology, technology is also more broad, can be used in the "home school links" roughly divided into low-frequency, high frequency, ultra-high frequency, 2.4g and other rfid technology. The technical categories are also different according to their own characteristics in the application. The following on each technology in the "home school" in the application and summary of the advantages and disadvantages. First, low frequency Low-frequency rfid operating frequency 125khz, the device type channel approach. Students wear the card through the channel can automatically read the information, due to the low-frequency reading distance limit, low-frequency channel placed in the distance of about 80cm. The speed of low-frequency rfid channel personnel is not ideal. Since the low frequency channel can not support simultaneous reading of multiple labels, only one person can pass through the channel at a time. This clearly can not meet the demand of the school when it is at the peak of school. Department integrators put more sets of channels to ease the way. The advantage of low-frequency rfid is that the low frequency is basically not affected by water and liquid, the human body wearing the label does not affect the channel reading effect on the card. Channel access to information can be locked to individuals, card-free personnel can alarm. This prevents students from entering or entering the campus without a card. Another low-frequency rfid label cheaper. According to his own technical characteristics, low-frequency rfid technology is more used in livestock husbandry management, on the one hand, the cost is not high, on the other hand the size of the livestock, move more slowly, read a tag in the low-frequency channel Form can be satisfied. Second, high-frequency close High-frequency rfid frequency band at 13.56mhz, divided into two types, one of the 14443 ($ 0.1401) agreement. The reading distance of this technique is about 10cm. In the use of "home-school communication", it is common to use the wall-mounted attendance machine to take the initiative to swipe the card, as well as to use the barrier-free access method. Of course, if the way is to use the wall hook is not card-less personnel alarm. So in the application of close-range high-frequency rfid also have businesses using the channel approach. Due to the need for staff to stay active credit card, rfid high-speed technology more slowly than the low-frequency rfid. But the close-range high-frequency rfid security is better, so more is used in colleges and universities or business parks for catering, bathing spending time to use. Basically, it is the smallest of all technologies in the rate of missed card information. Third, high-frequency long-range The 15693 ($ 43.2716) protocol is another protocol for 13.56mhz high-frequency rfids that differs from 14443 in that it can read farther distances. The use of high-frequency long-distance "home school pass" is more common, the use of access channels to read. Channels placed in the distance of 1 m -1.2 m, rfid high-frequency long-distance is widely used because manufacturers have produced a cascade of channels, using only three devices can be composed of dual-channel, four-piece device You can form a three-channel, placed the more channels, the less equipment used. For extra wide school gate placement can greatly save costs. Coupled with high-frequency long-distance channel can support multiple tags in the channel to read, access speed has been greatly improved. In addition, high-frequency long-distance information can be locked to individuals, for non-card access to the police can be timely warning. Effectively prevent outsiders from entering the campus. But one of the problems with high frequency long range rfids is that the price of the card is slightly higher. Fourth, ultra-high frequency UHF is commonly used in China is 915mhz operating frequency. It is in the low frequency, high frequency of different technical principles, through the principle of signal reflection to induction. Therefore, his reading distance, usually a UHF card reader nominal distance of 5-15 meters. Ultra-high frequency channels can often be very wide distances, allowing multiple people to pass side by side. However, at present, there is almost no application of UHF in home-school communication. The main reason for this is that ultra-high frequency signals can not penetrate the water and the human body can absorb a lot of energy when wearing UHF cards. At the same time, the UHF reading card must be at a certain angle with the antenna, the staff is out of the way when the antenna is right in front of the law, it is likely a sideways card was missed, resulting in leakage Reading rate is higher. In addition, the reading boundary of the UHF is not clear, and a number of persons wearing a card interact with each other seriously. UHF is currently used more in the logistics industry. Five, 2.4g active In addition to high-frequency long-range now there is a "home school pass" is applied to the 2.4g active technology. Its unique feature is the card will have a battery, through the initiative to launch the signal and make it even farther away. Active 2.4g and high frequency remote applications is different, it is installed on both sides of the school card reader, not a strict sense of the channel system, so you can make extra-wide, large school gate can also facilitate the staff access information Read Active 2.4g is also facing two serious problems, one is the battery life, because it is packaged in the card, once the battery runs out of students have to change the card, and even if the battery is not depleted, in use for some time Later, due to the weakening of the electricity, the transmitted signal will be weakened, the reading effect will be affected. Another problem is that 2.4g active technology has the same high directivity as UHF, and its performance is affected by humidity. A common problem is that cards can not be held by hand or placed in the bag behind the trousers. In summary, due to the rapid development of rfid, different technologies are becoming more mature. The applications it covers also cover all aspects of life. As part of the construction of "safe campus", the development of "home-school communication" has also been promoted by rfid. It is because of the application of rfid technology, we can now enhance the safety of children in school. Children are the future of the motherland. How to choose the right technology to do "home-school communication" is a question that all integrators and schools should consider. Danyang Weisheng Automotive Technology Co., Ltd , https://www.wizsinparts.com