How do HID Access Control Cards Work?

An HID prox card-based access control system consists of four main elements:

• Proximity (prox) cards
• Card readers
• Access control panels (controllers)
• User interface (host software)

How HID Prox Cards are Read

To read an HID access control card, you'll need each of the four parts of an access control system:

Every access control card carries a series of binary numbers (ones and zeros) which are used to identify the cardholder. HID offers a variety of card-types capable of carrying binary data, including magnetic stripe, Wiegand (swipe), 125 kHz Prox, MIFARE, and iCLASS contactless smart cards. It's important to note that two or more of these technologies can be included on a single card. For instance, it's quite common for contactless smart cards and proximity cards to also include a magnetic stripe.

Card readers are available for each of the card technologies mentioned above. Each HID card reader uses its own technology to read information from the card. In most cases, the binary data is converted to Wiegand Protocol and delivered to the controller.

After the controller accepts data from the receiver, its software processes the information and determines whether or not access should be granted. Typically, the controller analyses the length of the code, then breaks it down into its component parts. If the facility code, site code, and card number are accepted, then access is granted. The system can also be set up to only allow entry to certain individuals at specific times. Essentially, the controller is the lone part of the access control system where the binary data can be decoded, then acted upon.

The user interface (typically a terminal or software program), allows system operators and administrators to add and remove cardholders, adjust access privileges, create and modify schedules and lists, configure system hardware for alarm points and doors, monitor events in real-time, and generate reports.