A proximity card or prox card is a contactless smart card which can be read through proximity card readers without inserting it into the device. The cards themselves are part of the contactless card technologies. Held near a proximity or RFID card reader for a moment they enable the identification of an encoded number. This usually produces a beep or other sound to indicate the card has been read and access is granted. The presence of the person is also recorded depending on the workforce management software package you have.
Proximity Card Scanner
Passive 125 kHz cards, the more widely used type are powered by radio frequency signals from the reader device and so have a limited range and must be held close to the reader unit. They are used as keycards for access control doors and also for attendance clockings.
The card and the proximity card reader unit communicate with each other through 125 kHz radiofrequency fields by a process called resonant energy transfer. Passive cards have three components that are sealed inside the plastic: an antenna consisting of a coil of wire, a capacitor, and an integrated circuit (IC) which contains the user’s ID number in specific formats and no other data. The reader has its own antenna, which continuously transmits a short-range radio frequency field.
When the card is placed within range of the proximity or RFID card reader, the antenna coil and capacitor, which form a tuned circuit, absorb and store energy from the field, resonating at the frequency emitted by the reader. This energy is rectified to direct current which powers the integrated circuit. The chip sends its ID number or other data to the antenna coil, which transmits it by radio frequency signals back to the reader unit. The reader checks whether the ID number from the card is correct, and then performs whatever function it has been programmed to do for that ID number. All the energy to power the card comes from the reader unit, so passive cards must be close to a reader to transmit their data.
How do Proximity Card Readers and RFID Scanners work?
The unique badge or fob number issued to an individual is matched against their name in the time and attendance software so that when activated it can record attendance clockings or be used for door access on a multitude of readers and scanners.