How Proximity Cards and Readers Work

The following tech tip is a quick overview on how proximity cards and readers work together.

The proximity card reader is wired to an access control system panel. The wires carry power to the reader, and data from the reader to the panel. The Reader emits an electromagnetic field called the "excite field". This field has an elliptical shape as shown in Figure # 1 below.

As Figure 1 shows, the field extends behind the reader almost as much as in front.

When a proximity card is brought within the field, the card absorbs some of the energy from the field. The card converts this field energy to electricity, which allows the electronic circuits in the card to "turn on" and transmit its number to the reader. The reader then sends the card number to the access control system panel, which then looks up in its database to see if the card number is valid and if it has rights to open that door at this time. If the card is approved, then the control panel sends a signal to the door lock to unlock for a period of time.

The card data transmission distance varies with card type and reader type. Larger, more powerful readers do exist; which can energize some cards at a much farther distance. The distance at which a card will successfully transmit data to the reader is called the "Read Range". The read range is approximate and can vary depending on the details of the installation. Maximum range is achieved when the reader is mounted away from metal and cards are presented parallel to the reader face. This allows the reader field to power up the card transponder at a farther distance.

About ColorID, LLC
Every year, ColorID assists more than 1000 colleges and universities and their project managers personally oversee 700 custom projects each year, including many small and large recarding projects.  ColorID offers best-in-class products and solutions, including:  contactless, smart and financial cards from every major manufacturer, multiple ID printer platforms; transaction and point-of-sale software and hardware, a variety of handheld devices for identification and tracking applications and biometrics solutions, including fingerprint and iris readers. The company’s manufacturing partners include: Iris ID, HID, Fargo, Datacard, CardSmith, Gemalto, Zebra, NiSCA, Evolis, Allegion, Aptiq, Magicard, Brady People ID, Integrated Biometrics, Oberthur, NBS, Vision Database Systems and many others.

Contact ColorID at 704-987-2238 or toll free in Canada and the US at 888-682-6567. Visit ColorID on the web at: www.colorid.com or email ColorID at [email protected].

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