A mainstay of electronic door entry systems, the key fob has gone through many iterations since its inception in 1983. Early systems, used mainly for car doors, relied on line of sight and used infrared, but were highly susceptible to copying. Systems developed over time to use challenge-response authentication over radio frequency and now operate primarily over a passive radio frequency identification (RFID) tag, which allows the exchange of data through electromagnetic waves.electromagnetic lock manufacturers

Key fobs and cards are used with a variety of access control systems and offer a simple way for small businesses to manage entry into their facilities.

They have become increasingly popular due to their ease of use and customization options, which allow businesses to control who accesses what doors, see records of entries and exits, and adjust access as their workforce changes. Wondering if a key card/fob access system is right for you? Here's what you need to know.
Modern key fobs work through RFID, an intelligent barcode system that uses electromagnetic fields to identify and track data on "tags" that contain the stored information. The information is passed using radio waves.

The barcode system works similarly to a barcode you would see on the back of a physical product or the magnetic strip on your credit card – it requires a reader to gain the information.

To open a door using a key fob, you simply need to hold or wave your fob in front of the reader. Each key fob contains a microchip with a unique frequency that communicates with the reader and indicates that the door should be opened. Fobs can be programmed to allow levels of access for different uses. For example, a building manager's fob can be programmed to access all doors in a facility, while a receptionist's fob may be programmed to allow access to a few areas.