Interlogix TX-E721

The Interlogix TX-E721 is a passive infrared motion sensor that is designed for use with Interlogix alarm systems. The device is wireless and battery-powered, making it suitable for a large number of possible applications. The device also features advanced signal processing and pet-immunity for small animals weighing up to 40 pounds. Pet friendly technology in these devices assume that they are not positioned in stairwells or looking directly at furniture that pets may jump on. These situations can defeat the "pet immunity." Overall, the sensor provides outstanding performance, and it is an excellent motion detector for homes and small businesses.

Passive infrared (PIR) motion detectors work by detecting the levels infrared energy in a specific area. When there is a detected change in infrared energy, the sensor will activate and send an alert to the alarm system. A change in infrared energy is typically caused by a new person or object coming into the field of view of the sensor. However, the change in detected energy must be large enough, or else the sensor will not activate. This will lower the likelihood of false alarms. A user can choose between a standard sensitivity and a high sensitivity for the TX-E721. The standard sensitivity setting must be enabled for pet friendly environments. There are jumper pins on the back of the sensor for configuring its sensitivity.

The TX-E721 boasts a detection range of 35 by 40 feet. For maximum coverage, the sensor should be incline-mounted, facing diagonally down at a height of 7.5 feet. The device comes with its own mounting plate for easy installation. After installing the sensor, make sure to perform a walk test. This will help you ensure that the sensor is detecting motion properly. To enter walk test mode simply dismount the sensor from the mounting plate, and then reattach. While in this mode, a red LED light on the sensor will activate whenever motion is detected.

As an Interlogix Sensor, the TX-E721 communicates at a frequency of 319.5 MHz. This makes it compatible with all Interlogix wireless alarm systems, as well as any Qolsys alarm system equipped with an Interlogix legacy daughtercard. The device also features an integrated tamper switch. If anyone removes the back cover of the device, a tamper trouble is reported to the system to let it know that the sensor has been tampered with. If the system is armed during this time, an immediate alarm will occur. The TX-E721 should ideally be installed within 100 feet of the panel for optimal performance. However, it has been known to work from up to 500 feet away in open air. Finally, the typical battery life for the sensor is three to five years with normal use. When it's time for a replacement, a fresh CR123A battery can be inserted in place of the old one.