How does the access control reader work?

The reader emits electromagnetic waves at a fixed frequency. The frequency is generally 13.56 MHz. When the proximity card enters the electromagnetic radiation range of the reader, it triggers the coil on the card, generates current and triggers the antenna on the card to read the card. The transmitter emits a signal with card information. The reader converts the level signal into a digital serial number, transmits it to the local controller with Wiegand protocol, and the local controller uploads the information to the upper controller. It is finally uploaded to the access control server. The access control server compares the card number with the information in the database to obtain all the card information.

The current mainstream readers generally support a maximum reading distance of 100mm, operating frequency (13.56MHz), support for ISO standards (ISO14443A/B), and with LED sound and light alarm (red and green).