possible. For additional information, contact the
base radio officer or the Naval Electromagnetic
Spectrum Center at (202) 433-0689. OPNAVINST
2400.20E is issued by OPNAV Code N60 (previous Code
OP941), telephone (703) 695-7284.
**************************************************************************
The system shall be a full duplex, supervised RF polling specifically
designed for alarm data communications with components manufactured by one
manufacturer. The system shall operate in the very high frequency (VHF),
[134 to 154] [_____ to _____] MHz band. The system shall interface
directly with the IDS hardwire data link from control communicator to the
central alarm reporting location. The system shall also translate (reduce)
the data rate for RF transmission, modulate and demodulate the data signal,
and transmit and receive IDS data. Provide a factory-tested complete RF
link which both automatically and upon operator command transmits a signal
with a unique identification from the central alarm monitoring location to
control communicator locations. Message receipt at control communicator
location shall be ignored by other control communicators except the
addressee. The communicator with the correct address shall decode the
interrogation signal and respond to interrogation with status of reporting
sensors. If the addressee fails to respond, reinterrogate. Failure to
respond a second time shall cause a line supervision alarm. Remote units
in the RF system shall be individually polled in turn. Polling response
time and transmission data rate, data error rate, and equipment reliability
shall ensure that overall IDS alarm annunciation time reliability is not
degraded. Provide RF transmitters, receivers, or transceivers in
sufficient quantities to meet specified requirements. RF link
transmissions shall be on one or more of the frequencies within the
specified band as required to meet the specified requirements and shall
neither interfere with other IDS components nor facility electronic
components. Provide transmitters which are in accordance with applicable
requirements of 47 CFR 15. Message types and content shall be identical to
those transmitted by other portions of the IDS data communications
subsystem. IDS alarms sent by RF link shall not fail to be transmitted by
RF link due to events occurring in "off air" periods. The RF link shall
provide message transmission priority in the following order:
a.
Intrusion alarms
b.
Tamper alarms
c.
Access denial alarms
d.
Other alarms on a first-in, first-out basis including loss of
communication signal, fail-safe, low battery, and power loss.
Provide [omnidirectional, coaxial, half-wave dipole] [_____] antennas for
alarm transmitters and transceivers with a driving point impedance to match
transmission output. Antennas and antenna mounts shall be corrosion
resistant and designed to withstand wind velocities of [161] [_____] km/h
[100] [_____] mph and physical damage caused by vandalism. Antennas shall
not be mounted to any portion of the facility fence or roofing system.
Antennas shall be furnished from the same manufacturer as the rest of the
RF link. Provide coaxial cable in lengths as required. Cable shall use
PL-type fittings or connectors, properly protected against moisture.
Cables shall match the output impedance of the transmitters.
SECTION 13702N
Page 26
Previous Page
