Double Pass Coverage - Interlogix FlexZone Series Product Manual

Chapter 1: System planning
to verify alarms and alarm location. When setting up the camera views, ensure
that there is at least 6 m of overlapping coverage at each zone boundary.
Service loops (flexible fences)
Service loops provide extra sensor cable along the fence to make cable repairs.
Allot 75 cm of cable each 50 m for a service loop. Locate the U-shaped service
loops at fence posts.
Drip loops (flexible fences)
Drip loops raise the connector above the sensor cable to prevent water from
running along the cable and accumulating in the enclosure. Drip loops also
relieve strain resulting from temperature changes that cause the cable to expand
and contract. Form the drip loop by raising the connector 15 cm above the level
of the cable run. Allot 50 cm of cable for each splice or termination.
Gate bypass
If there is a gate within a FlexZone sensor zone, you require a sufficient amount
of inactive cable to bypass the gate, even if the gate is protected by sensor
cable. Secure the bypass cable and bury it in PVC conduit. See Figure 45 on
page 38 for an example of a bypassed gate, which uses a microwave system to
provide security across the gate.

Double pass coverage

For FlexZone installations which require double passes of sensor cable, you use
both cable sides of a processor to provide software zoning and precise target
location. To accomplish this the processor is located at one end and the two
sensor cable sides run parallel for up to 300 m along the fence in an upper and
lower cable pass. The ends of the two sensor cables are terminated or spliced
together. To enable precise target location, the detection start points of both
cables must match, and both cables must be of equal length and have identical
features (e.g., service loops, sensitivity loops, etc.). Each FlexZone processor
can provide double pass coverage for up to 300 m of fence.
FlexZone™ Product Guide
11