What is an Interior Follower Zone?

An interior follower zone is a system zone that has a Response Type of interior follower. With this Response Type, the security system will trigger an immediate alarm if the sensor is activated while the system is set to arm away. Interior follower is often used with indoor motion sensors.

The idea with interior zones is that the user will want an alarm to occur if the sensor is activated while the system is armed away, but not while the system is armed stay. With armed stay, the implication is that a user is still on-site and moving freely throughout the building. But with armed away, there is nobody in the building, and there should be no motion present. With that in mind, any "interior" Response Type will only have the sensor remain active when the system is set to armed away.

If an interior follower zone is activated while the system is armed away, an immediate alarm will occur. But this is one very important exception to this rule. If an interior follower zone is activated after an entry delay zone, then an immediate alarm will not occur. Instead, the system will continue to follow the guidelines of the entry delay zone and allow the user to disarm the system within the entry delay period. In this sense, the interior follower zone follows the entry delay zone. The reasoning is that a user may enter the building through a normal entrance and activate the entry delay period. They might then activate the interior follower zone when they go to disarm the system. In that case, a user wouldn't want an immediate alarm to occur on their system.

Interior follower zones are most commonly associated with motion detector. A motion detector will activate simply because of a person walking by the sensor. These sensors are used for the purpose of detecting activity when there should be nobody inside a building. If a system is set to armed away, then there should be no motion in the building. In that situation, it is very important that a motion sensor properly activates. But if a system is set to armed stay, then there will still be somebody in the building. The user would still want to move freely throughout the building, and they wouldn't want the interior follower motion sensor to activate and cause an alarm. But please note that an interior follower motion sensor will not be activated in armed away if the sensor has been bypassed.