What is an Alarm System Key Fob and What Does it Do?

An alarm system key fob is a handheld device that is used to perform system functions. A key fob works by sending wireless communication signals to the alarm system. The alarm system will recognize any incoming signal and then perform the function that is assigned to that key fob zone.

A key fob provides a user with a quick way to control their alarm system. The device can be carried on them at all times, and a quick button press will allow them to perform a wide range of functions. Each button on the key fob can be assigned to perform a different system function. However, a standard four-button key fob will typically be used to disarm the system, arm away, arm stay and trigger a panic alarm.

On Honeywell systems, each key fob command uses its own wireless zone on the system. Some systems organize these as key fob zones, which are considered separate from wireless security zones. So a four-button key fob that is used to perform four different system commands will require four key fob zones on the system. A key fob can only be used if there are zones available for it on the system.

In terms of communication, key fobs are very similar to wireless security sensors. Alarm systems accept incoming wireless signals using a wireless receiver. The key fob will need to communicate using a wireless frequency that is compatible with the system's wireless receiver. For reference, Qolsys and Interlogix/GE use 319.5 MHz, Honeywell and 2GIG use 345 MHz, and DSC uses 433 MHz.

Key fobs can also be used for home automation. By setting a key fob button to perform as an input only, it can be used to trigger Z-Wave scenes. This will allow a user to activate their Z-Wave devices with the press of a button. However, each key fob input can only be programmed to perform one Z-Wave scene.