Interlogix FlexZone Series Product Manual page 16

Chapter 1: System planning
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For flexible fences greater than 4.3 m tall - a double pass of sensor cable at
1/3 and 2/3 the fence height.
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For vinyl coated fences - a double pass of sensor cable at 1/3 and 2/3 the
fence height.
Note: If the lower edge of the fence fabric is embedded in a concrete footing, or
below ground, use an additional cable pass on the lower section of fence to
increase the sensitivity.
Note: If the fence framework includes an intermediate (middle) rail, it may require
a double cable pass, with one pass above the rail and one pass below the rail.
Figure 6: Cable spacing recommendations
rigid fences
double pass
h > 2 m (6.5 ft.)
single pass
max. h = 2 m (6.5 ft.)
Non-detecting cables
For instances where the processor is located away from the protected fence,
outdoor rated, shielded 75 Ohm coaxial cable with a solid copper center
conductor can be used as lead-in cable (e.g., RG6). For cable bypasses along
the perimeter, FlexZone sensor cable is used. The bypass cable is set to inactive
(Zone 0) in software and will not report sensor alarms. Non-detecting FlexZone
cable must be well secured to prevent any cable motion. The length of coaxial
cable that is used for lead-in must be deducted from the detecting cable length
(maximum cable length detecting plus non-detecting = 300 m).
Fence corners and heavier gauge posts
Corner posts and heavier gauge support posts tend to dampen the fence's
vibration transmission characteristics. Therefore, use cable loops at corner posts
and heavy gauge support posts, to increase the sensitivity. Each sensitivity loop
requires approximately 3 m of sensor cable.
Zone demarcation loops (flexible fences)
Zone demarcation loops may be used at software defined zone boundaries for
improved location accuracy. It is possible that an alarm that occurs very close to
a software defined zone boundary could be reported in the adjacent zone (± 3
m). Zone demarcation loops add extra sensor cable at zone boundaries to help
ensure that an alarm is reported in the zone in which it occurs. Allot 3 m for each
zone to adjacent zone boundary. Rather than using extra cable for zone
demarcation loops, overlapping CCTV coverage can provide visual assessment
10
flexible fences
single pass
max. h = 4.3 m (14 ft.)
1/2 h
1/2 h
double pass h > 4.3 (14 ft.)
double pass
fences with a middle rail
1/4 h
1/4 h
1/4 h
1/4 h
FlexZone™ Product Guide
and vinyl coated fences
1/3 h
1/3 h
1/3 h