The function and technical type of the most fire d

2022-07-31
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The role and technical type of access card reader

the role of access card reader

with the rapid development and popularization of digital products, we often exchange data between different digital products, and the card reader is a product that performs such a function. As the name suggests, a card reader is a device that reads a memory card

the access card reader is a device used to read the data (biometric information) in the card. It is an access control component that directly contacts the user. Its function is to read and identify the identity information of the entrant. Generally, the identity information can be customized by the colorful style, such as card number, personal password, fingerprint or other important information used to identify and prove personal identity

the card reader is an important part of the access control system and the key equipment for the signal input of the access control system. If the access control system is compared to a person, the card reader is like a person's eyes. It is related to the stability of the whole access control system. If the controller and electric lock of an access control system are good, and if there is a problem with the quality of the card reader, it will also cause the door to fail to open, which will affect the acceptance of the project and the safe and stable installation and use of the mixer

the technical type of access card reader

we can divide it by radio frequency and ISO standard:

low frequency 125khz: the radio wave length is 125kHz, and the standard proximity technology is used. As a relatively old standard, it has been gradually replaced by high-frequency technology

high frequency 13.56mhz: the radio wave length is 13.56MHz, allowing reading, writing and encryption to improve security. Due to higher communication speed, it is more suitable for special security and anti-counterfeiting authentication for biometrics and processing. High frequency technology has become the mainstream development trend in the current market

there are two more popular international standards in high-frequency technology:

iso14443: international standard non-contact technology, usually the card reading distance can reach 10cm. The advantage is that the processing speed is fast, which is suitable for information transmission with a large amount of data. For example, biometric technology provides an opportunity to show. Iso14443 is subdivided into two standards a and B. 14443a is popular in the transportation industry, while 14443b is popular in the banking industry

iso15693: international standard non-contact technology, visibility technology, usually the card reading distance is greater than 10cm. Its advantages are longer read distance and lower power consumption

another division is based on the operation mode of the card reader:

the so-called operation mode refers to the data transmission format between the card reader and the controller

· most wiegan manufacturers use this mode. The Wiegand data format transmits the specific number of the identity card from the card reader to the controller through two data lines in a series of numbers 0 and 1. This transmission process is one-way and can only be transmitted from the card reader

· f/2f (frequency/twice the frequency), also known as Manchester decoding method. Is a unique model owned by GE. The f/2f format transmits data through a data line. The data is transmitted as a string of 0 and 1, but the first ten digits remain 0. This monitors the bandwidth of the card reader for the controller and then determines that the subsequent number is 1 or 0. Monitoring f/2f is the most complex functional mode. The patented monitoring f/2f mode enables two-way communication from the card reader to the controller. Every second, the card reader sends a "I'm still alive" signal to the controller. The controller immediately sends back a receipt message to confirm that the communication is smooth. However, if the line is cut off or shorted, the card reader will not be able to communicate with the controller. The reader is still sending messages per second. If the reader cannot receive the receipt message, it will send 3 messages per second instead. If the receipt is not received for more than 1 second, the card reader will send a monitored alarm, the red indicator will flash, and the card reader will send a beep that "solves the impact of human factors on the experimental results". Because the card reader and the controller communicate every second, the open circuit or short circuit will be quickly detected and an alarm will be triggered, which creates a very safe system. (end)

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