Using the FD322 as a Cable Break Sensor

The Fiber Defender® product line offers a diverse range of solutions for a wide scope of security applications. Our products are trusted to protect military, nuclear, industrial, commercial, and residential applications. The FD322 combines Fiber SenSys’ legacy of high-security and high-reliability with simple configuration requirements at a very competitive price.

Typically applications with Fiber SenSys perimeter security products involve detection of intruders that are trying to climb, cut, or crawl through the fence. In these applications, a fiber-optic cable is attached to the fence, and an alarm processing unit (APU) is connected to the fiber. The APU launches laser light into the fiber, and by measuring the transmitted and reflected light, the APU can tell when the fiber is disturbed by an intruder trying to breach the fence.

In some applications, the APU is tuned to detect when the optical fiber is broken. These applications arise when the environment has lots of vibration and noise, and valuable hardware cannot be accessed without breaking the fiber. An example of this is the security of medical devices (see Figure 1). Multi-mode optical cable such as SC-4 is recommended for cable break detection applications.