The keypad alarm system is a basic alarm system with a low-voltage circuit that involves sensors on doors and windows. When a window or door is opened, the electricity through the sensor is interrupted and the alarm is triggered unless a code is typed into a security keypad. Some alarms also use motion sensors which can be triggered when motion is detected inside a monitored area.

Keypad alarms offer several advantages over other alarm systems and are available in both wired and wireless versions. They allow the user to control all access points within a structure, providing access only to select people. These alarms can be activated even if the user isn’t in the area.

Wired keypad alarm systems connect to a control panel. The wires, hidden in walls and various crawl spaces, go to sensors placed on doors and windows and within the keypads themselves. Instead of wires, wireless keypad alarm systems rely on radio transmitters to send signals to each other. The same alarm effect is created when doors or windows are opened without entering the code into the numeric keypad.