response. Failure of the detector to return a data burst, or
return an incorrect response, shall initiate an alarm.
d.
RF link supervision: System shall consist of link supervision
components which provide a line supervision alarm declaration at
the annunciation end of the link in approximately 2 seconds after
the system has verified a problem by repeating the same signal no
less than nine times during a period of 30 seconds or less.
2.4.16.2
Hardwire
a.
Hardwire shall utilize electrical conductor lines. Alarm
electrical lines shall not rely on current path except for
electrical wires; neutral conductors of electrical distribution
systems shall not be used as signal transmitters. Conductors
outside the protected area shall be [shielded cable] [buried]
[[installed in rigid galvanized steel conduit.] [installed in
electrical metallic tubing (EMT)] as specified in Section 16402
INTERIOR DISTRIBUTION SYSTEM]. Supervision circuitry shall not
initiate nuisance alarms in response to normal line noise,
transients, crosstalk, or in response to normal parametric changes
in the line over a temperature range of minus 35 to 52 degrees C
30 to 125 degrees F. Ambient current levels chosen for line
supervision shall be sufficient to detect tampering and shall be
within the normal operating range of electrical components. Line
supervision and tamper alarms shall be reported regardless of mode
of operation. Provide hardwire links as specified in UL 1076 and
Section 16402 INTERIOR DISTRIBUTION SYSTEM for interior
applications with additions and modifications specified herein.
Conductors shall be copper. Conductors for links which also carry
ac voltage, shall be No. 12 AWG minimum; single conductors for
low-voltage dc links shall be No. [14] [16] AWG minimum.
Conductors shall be color coded. Conceal wiring in finished areas
of new construction and wherever practical in existing
construction if not otherwise precluded by the Government.
Identify conductors within each enclosure where a tap, splice, or
termination is made. Identify conductors by plastic-coated,
self-sticking, printed markers or by heat-shrink type sleeves.
Connect sensors, control units, and communication devices so that
removal will cause a tamper alarm to sound. Pigtail or "T" tap
connections are not acceptable. Each conductor used for identical
functions shall be distinctively color coded. Each circuit color
code wire shall remain uniform throughout circuit.
b.
Communication link from sensor to control unit shall be by
dedicated circuit. An alarm condition shall be indicated by the
opening or closing of a relay contact. Analog signals shall be
converted to digital values or a relay closure or opening within
76 meters 250 feet of the sensing point. Communications from
control unit to central alarm reporting and display processor
shall operate in a continuous interrogation and response mode,
using time-multiplexed digital communications techniques at a data
rate of [5.12] [10.24] [_____] kilobaud. Interrogation and
response communications between the control unit and central
processor shall be half-duplex, bidirectional on one dual twisted
pair cable, one pair for interrogation, one for response, which
may have one or more parallel branches. Individual control unit
lines shall be 22 AWG or larger wire. Connect control wires in
parallel to the hardwire link. Communications system shall
SECTION 13703N
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