The ID card is to catch the front of the punching machine. Immediately after the beep sound your attendance falls. This is called Field Communication or NFC. Exchange of information between each other on a short distance between two devices. This information exchange is again two types - active and passive. Passive NFC devices include small transmitters such as NFC tags. These tags are very small and round.
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These tags are attached to the ID card. The feature of the NFC tag is that it works without any power source and provides information to other nearby NFC devices. Typically, the hard cover outside the ID card is inserted inside the NFC tag. This NFC technology provides information via radio waves such as Bluetooth, WiFi or other wireless signals.
Passive NFC tag stores energy and sends data to the active device when an active device that comes in the field of electromagnetic field creates. Not just the office punching machine, the NFC tag is now also being used on smartphones. This tag, which has been launched recently on Samsung galaxy J3.