Access control system and the difference between active and passive card?
Passive card: the card itself does not carry the battery, is the card reader to launch the electromagnetic chip to activate the chip chip, the chip will send the card number data to the reader's battery wave back to the card reader, There are two kinds of 125K, 13.55M, this distance is relatively close to only 2 ~ 15CM, but also the 915M can do 1 to 15 meters.
Active card: the card must be equipped with a battery inside the card is the initiative to send data to the card reader, through the use of the frequency is generally 2.4G or 3.8G, the reader distance, you can do between 10 to 80 meters , Depending on the situation.
