Von Duprin Monitor Strikes

Monitor strikes replace standard lock strikes with a signal switch designed to monitor latch position. A Tripper Switch inside the strike triggers the signal once the latch is fully engaged in the strike.

The purpose is to monitor the latch position from a remote location. High security buildings have monitoring stations that track door usage. An opened door is a breach of the system and the monitoring station is alerted each time the door opens.

The Tripper Switch performs much the same as a light switch. But instead of a finger flipping the switch on and off it is the latch that does the work. A fully engaged latch causes a signal to be sent back to the monitoring station, indicating the door is secure. An opened door causes the signal to stop and the monitoring station is alerted.

Remote monitoring stations use a series of lights to monitor door activity. Each door uses a set of red and green lights to indicate door status. A red light indicates the door is closed while a green light shows the door is in use.

Many times the station will also employ camera feeds that allow a guard to visually monitor door traffic as well. Should any door's light change from red to green the guard can check the video monitor to watch that particular door.

Remote stations can also wire into an alarm system that triggers upon unauthorized use of a door. An example would be a system designed to be completely locked down after 10:00 PM. Should any door open after 10:00 PM the remote monitoring station is alerted which in turn triggers the alarm system.

For many years the common method of monitoring a door was to use a Magnetic Switch. One portion of the switch mounts into the frame and the other into the door. When the door is closed the two halves make contact. This contact completes a wire loop circuit causing a signal to be sent.

The problem with this method of door monitoring is that it only indicates the door is closed. It does not indicate the door is locked. Just because a door is closed does not mean it is latched and locked. Doors can close without being locked.

Monitor Strikes solve this problem by monitoring the latch position, not the door position. A signal will only be sent when the door is securely locked.