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DD243:2004 Code of practice for intruder alarm systems designed to
generate confirmed alarms
All new monitored alarm
systems that require a Police response must use a method of alarm
confirmation. Alarm confirmation methods are used to reduce the
possibility of false alarms and thus reduce the time wasted by the Police
in attending systems which have false alarm activations.
The
British Standard DD243 details what methods of confirmation may be used
and how the system must be configured. In particular it details how a
system may be armed and disarmed in order to reduce the likelihood of
false activation by the system user. It applies to monitored systems
installed throughout England, Wales, Northern Ireland and Scotland and is
a requirement of both ACPO and ACPOS security systems policy.
Under DD243 there are 3 methods of alarm confirmation which may be used:
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Audio - Audio confirmation systems requirements For audio
confirmation systems the audio equipment may be triggered by an
Intruder Detector Audio listing device (ALD). Audio systems must also
provide sequential confirmation. |
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Video - Video confirmation system requirements Video equipment
may be triggered by Intruder Detectors & Video Motion Detectors (VMD).
Video systems must also provide sequential confirmation.
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Sequential - Sequentially confirmed activation requires two
independent detectors to activate within 30 to 60minutes. The 30 to 60
minutes will be programmed at the control unit. |
Methods of Unsetting
Unsetting must be carried out in a manner which minimises the possibility
of a confirmed alarm being generated during unsetting. Unsetting options
are:
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Entry to the supervised premises is prevented whilst the alarm system
is set. |
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Entry to the supervised premises is prevented until means to generate
a confirmed alarm have been disabled. |
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Opening the entry door disables all means of confirmation.
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Completion of unsetting is carried out using a portable “ancillary
control equipment”, e.g. a “key fob” similar to that used to
lock/unlock a car |
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Unsetting in association with an ARC, e.g. the ARC unsets the system
remotely following secure procedures. Designing an intruder alarm
systems such that a confirmed activation is generated when appropriate
is not necessarily as straight forward as it first appears. This is
particularly true of sequential confirmation when great care must be
taken to ensure a confirmed alarm is generated when necessary.
Installers should also be careful to specify what action is required
when an unconfirmed alarm is generated, e.g. informing a key-holder or
guarding company. Selecting the appropriate means of unsetting is also
essential as the ability of a system to generate a confirmed
activation during unsetting is generally disabled.
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Alarm Signalling
In
addition to the above methods, confirmation of an alarm activation also
extends to the alarm signalling system where dual path transmission is
installed. If any of the following incidents occurs an alarm is deemed to
be confirmed and the Police called:
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A signal transmission path cut followed by an alarm signal
transmission |
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Alarm signal transmission followed by a transmission path cut |
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Cuts on both signal transmission paths
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