I’m back ! Had a nice Holiday? I’m back ! Had a nice Holiday? Today we are talking PROXIMITY TECHNOLOGY Today we are talking PROXIMITY TECHNOLOGY

What is a Proximity Card ? A proximity card - or prox card - is a "contactless" or hands-free card which can be read without inserting it into a reader device, as required by earlier magnetic strip cards such as credit cards and "contact" type cards. The proximity cards are part of the Contactless card technologies. Held near an electronic reader for a moment they enable the identification of an encoded number. The reader usually produces a beep or other sound to indicate the card has been read. Proximity cards typically have a read range up to 50 cm (< 15 inches) which is the main difference with contactless smartcard with 2 to 10 cm (1 to 3 inches). The card can often be left in a wallet or a purse, and read by simply holding the wallet or purse near the reader.

Proximity cards can’t hold more data than a magnetic strip card. They are all proprietary, which means that there is no compatibility between the readers of a specific brand and the cards of another brand. However, manufactuers are expanding support for multiple formats. This is the case of all existing memory based brands (Mifare Classic, iClass, etc…) This technology is a READ only technology.

125 kHz cards More widely used Powered by radio frequency signals from the reader device Limited range Must be held close to the reader unit Used as keycards for access control doors in buildings Passive Cards 125 kHz Prox cards Powered by an internal lithium battery Have a greater range – up to 2 meters Battery eventually runs down May have to be replaced after 2 years Used in barrier and gate applications Active Cards

How does it work? The card and the reader unit communicate with each other through 125 kHz radio frequency fields, by a process called resonant energy transfer. Passive Card’s Components *** contains the user's ID number in specific formats and no other data. The reader unit has its own antenna, which continuously transmits a short range radio frequency field.

When the card is placed within range of the reader, the antenna coil and capacitor, which form a tuned circuit, absorb and store energy from the field, resonating like an electrical version of a tuning fork. 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. Since all the energy to power the card comes from the reader unit, passive cards must be close to the reader to function, and so have only a limited range. A proximity sensor is able to detect the presence of nearby objects without any physical contact.

Main advantages of proximity cards over magnetic stripe cards and barcodes

Interesting fact : One of the reasons Proximity technology was developped, was because pharmaceutical companies research labs required a hands-free secure method to unlock and lock doors. All of this started in the early stages of Aids research Interesting fact : One of the reasons Proximity technology was developped, was because pharmaceutical companies research labs required a hands-free secure method to unlock and lock doors. All of this started in the early stages of Aids research

Conclusion Most modern access control systems use proximity (also know as RFID ) cards or key fobs as the ‘credentials’ that enable users to gain access into restricted areas. They store a specific number and format. Proximity readers can read the information using radio frequency communication, making actual contact with the card unnecessary. By simply holding the card or fob close to the reader, the holder’s details can be read and checked quickly so that a decision whether or not to grant access can be made in an instance. The technology used in proximity cards and readers can vary from manufacturer to manufacturer, and there are many standard and proprietary systems on the market. It is important to be aware of this when designing a system. Talk to you next month!