The benefits of LPS 1277 - A specifier's guide
Alarm transmission equipment (ATE) forms a vital part of any alarm system installation. It guarantees an
alarm event is reliably and quickly transmitted to the alarm receiving centre. This then ensures a prompt
and appropriate human response.
The LPS 1277 approval scheme brings all the various Alarm Transmission System (ATS) requirements relevant
to the UK fire and intruder alarm market together. It also deals with any omissions and ambiguities of existing
European and national standards. The aim is to help specifiers and end users to confidently select or recommend
ATS – through reference to a single approval scheme – at a performance level (e.g. ATS 1 through to ATS 6)
and type (e.g. single/dual transmission path) appropriate to the risk being managed.
The requirements of LPS 1277 Issue 3.0 are based on the BS EN 50136 and BS EN 50131 series of European
Standards. While it builds on and clarifies these Standards, typically in areas relating to intrusion and hold up
alarm systems, LPS 1277 does not in any way undermine their use or future development, as BRE Global’s
Martin Staples explains.
The European Standards set minimum requirements that should be met – in this case by alarm transmission
systems (ATS) – but this does not preclude specific market demands from requiring more. Indeed, exploiting
capabilities/requirements above the minimum makes for good business practice, enabling quality providers to
stand out from the crowd. Many in business will be familiar with the term ‘differentiate or die’.
LPCB and BRE Global have a long history of helping to develop many of the national and international standards
in the areas of security, fire, sustainability and the built environment, which are published as BS, ISO, IEC and
EN standards.
National and international standards are the preferred basis for LPCB approval schemes as demonstrated in
LPCB's Red Book listings (www.redbooklive.com) where, for example, numerous products are approved to the
BS EN 54 range of fire alarm standards.
LPCB only produce Loss Prevention Standards when:
•
no national or international standard(s) are available
or
published standards do not adequately cater for the needs of a relevant stakeholders
•
In this case, published and latest draft revisions of BS EN 50136 and BS EN 50131 do not fully address the
needs of specifiers operating in the UK – for example the need to recognise the ATS requirements of BS 8243
(formally DD 243), a code of practice dealing with the generation and transmission of confirmed alarm
conditions.
By evaluating ATS products in a comprehensive, impartial and objective manner, irrespective of the technology
used, a level playing field is created. This allows specifiers to select ATS by generic performance requirements,
rather than by particular provider or product, and so avoids uncertainty over the nature of individual ATS products
and their key performance parameters.
In addition to outlining clear performance requirements, LPS 1277 contains (in ANNEX C) guidance for
equipment installers, which the suppliers of LPS 1277 Issue 3.0 approved ATE are required to include in their
installation instructions.
This guidance covers good ATS installation and configuration practices, and clarifies current installation
standards. For example, it defines what should be considered as site network equipment (i.e. any part of the
alarm transmission equipment or other equipment in the end user's premises, which is key to the normal
functioning of the ATS). The guidance aims to ensure that clear identification and adequate protection will help to
minimise the risk of criminal compromise or accidental disconnection.
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ANNEX C is only a means of drawing good practice to the installer’s attention, as ATE suppliers are clearly not
able to take responsibility for the actions of installers. However, an alarm company claiming to have installed LPS
1277 compliant signalling must feel an obligation to be able to demonstrate that it has paid some regard to the
supplier’s installation instructions. Also, other specifiers such as insurers and end users may make adherence to
ANNEX C a formal part of their requirements.
Many of the issues tackled by LPS 1277 Issue 3.0 are likely to be relevant to insurers, and are highlighted in the
recently published RISCAuthority Guide S15 - Security - Guidance on evaluating the performance of alarm
transmission systems for use with intrusion and hold-up alarm systems.
Comparing the features of LPS 1277 with Appendix C (Summary of BS/EN issues) of the RISCAuthority guide
(Fig. 1), clearly illustrates how the LPCB approval scheme can ease much of a specifier’s work and concerns,
when considering the performance and reliability of an ATS and its related alarm transmission equipment.
The text of Appendix C has been reproduced in Fig 1 with the kind permission of The RISCAuthority. A copy of
their full Guide S15 can be downloaded from www.riscauthority.co.uk
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Figure 1
•
Should a level of ATS availability be required?
Availability is a key performance parameter for any alarm transmission system (ATS) – without an operational
network no message can be sent. The LPCB approval scheme recognises this and requires that availability be
measured at the time of testing, based on the framework in BS EN 50136, which had been missing from EN
50131-1. The resulting performance parameter [A] of measured availability is displayed in the Red Book
listing. It is checked annually and, if appropriate, updated.
•
Are claims of the percentage of time that an ATS is available based only the period an associated
alarm system is set, or on the combined period of set and unset states?
In LPS 1277 the percentage of time that an ATS is available is based on the entire time the ATE remains
powered, which includes both set and unset states.
•
Is a dual path ATS one with two different ATSs, or one ATS with two paths?
LPS 1277 clarifies that a dual path ATS is one ATS with at least two paths of different technologies, each
capable of performing fully in place of the other. The Red Book product listing entries declare the number of
transmission paths available and their associated technology type (e.g. PSTN, Broadband or GPRS etc).
•
In DP ATS should the 'main ATS' fault reporting time be taken as applying to the whole ATS or the
primary path only?
The reporting time of the secondary transmission path of dual path ATS is permitted to be longer (i.e. less
frequent check signals) when in standby mode, provided the primary transmission path is fully operational.
LPS 1277 requires that the reporting time of the secondary path 'steps-up' to that of the primary path should
the primary path be lost.
By way of information for the specifier, the actual fault reporting performance measured during testing to LPS
1277 is shown in the Red Book listing by the corresponding parameter [T] for each combination of path failure.
See the example below for a typical ATS5 alarm transmission system;
Loss of Primary path only
(i.e. secondary path remaining operational)
Loss of Secondary path only
(i.e. Primary path remaining operational)
Loss of Secondary path whilst operating in 'stepped up' reporting mode
(i.e. the loss of Secondary path some time after a previous loss of the Primary
path)
Reporting catastrophic failure of ATS commensurate with
3
T4
(180s)
T3
(300mins)
T4
(180s)
Enhanced
ATS 5
(210s)
•
If an ATS has two paths, should the secondary path;
- be capable of fully matching (stepping up) its performance level to match that of the primary once
the primary is lost?
- be permitted to have a longer fault reporting time when in stand-by mode?
- be actively checked for correct operation immediately upon loss of the primary, or be passively
assumed to be operational pending expiry of the 'stepped up' fault reporting time?
- be able, through immediate checking within a defined short period, to quickly contribute to a
designation of catastrophic (total) ATS failure?
- have a defined period of operation in 'stepped up' mode?
A fundamental requirement of the LPS is that the secondary path will step-up to match the performance of the
primary path in the event of primary path failure.
In fact, all the performance parameters associated with the secondary path should normally be the same as
those of the primary, with the exception that checking of the path integrity (e.g. polling) can be performed less
frequently whilst the primary is fully operational. Checking the integrity of the secondary less frequently can
significantly reduce the running costs associated with an ATS.
In order to meet the reporting time requirements of LPS 1277 for the different combination of path failures, the
secondary path must be actively checked immediately on detection of failure of the primary path.
An additional short duration is permitted for detection of catastrophic ATS failure (30s for enhanced ATS 5 and
60 for enhanced ATS 4Plus and below).
The introduction of the requirement to detect and report catastrophic failure is denoted in LPS 1277 by the
term 'enhanced' ATS performance (e.g. enhanced ATS 5), thus differentiating the performance levels of LPS
1277 from those of the current EN standards.
Clause 5.2 of LPS 1277 requires the ATS to remain in the 'stepped up' mode for a minimum of 96hrs, which is
intended to allow for extended weekend periods.
•
If a duplicate primary path exists should it;
- be capable of fully matching the performance level of the primary once the primary is lost?
- require any background checks when not in use?
- be checked for correct operation immediately upon loss of the primary, and if so within or outside
the primary path fault reporting time?
- have a defined period of operation when in use?
The purpose of a duplicate path is to add extra resilience, for example, by operating two primary paths
simultaneously. If communication over one of the primary paths ceases momentarily, as can happen with a
GPRS radio link due to changes in atmospheric conditions, and the duplicate primary carries on working.
Theoretically there has been no loss of the primary path and therefore no need to 'step-up' the secondary
path reporting.
During testing to LPS 1277, the performance of any duplicate path is measured to confirm that it does match
that of the designated primary path (or if applicable, secondary path).
In the event of failure of the primary path, the LPS requires any duplicate primary path to immediately take
over within the primary path reporting time. Checking of the duplicate primary path, by polling or equivalent
means, will then commence at a rate sufficient to maintain the fault reporting time at least equal to the
performance of the claimed ATS rating of the primary path.
Once checking of the duplicate primary path is initiated, its fault reporting time will persist until any primary
path fault is cleared and normal service resumes, or a period of 96 hours elapses (whichever is the sooner)
– in which case a suitable path failure report will be passed to the AE. In either case, the duplicate path
reporting function is then permitted to return to normal.
There is no requirement to check availability, correct operation or operational communication of the duplicate
path whilst the primary path is functioning correctly. If both the primary and duplicate paths have failed the
ATS is expected to revert to operation on the secondary path in 'stepped-up' mode.
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•
If the fault reporting times of an EN 'grade' 3 DP ATS are not generally considered adequate, what
alternative figure should be followed?
A new 'enhanced' ATS performance level has been added to LPS 1277 Issue 3.0 – ATS 4Plus. This provides a
10 minute reporting time which bridges the gap between the 5 hour reporting time of ATS 4 and 3 minutes
associated with ATS 5 (as specified by EN 50136-1-1:1998). Albeit the new revision of EN 50136 attempts to
reduce the gap, but at 30 minutes this is still considered too long. Realistically, 10 minutes represents the
maximum amount of time that primary path failure should be tolerated. If set longer, any related criminal event
is increasingly likely to have concluded by the time a response arrives.
•
Should fault reporting times of each path be determined by end to end polling or Site ATE?
LPS 1277 requires fault reporting of each transmission path to be determined by end to end polling or
background checking, rather than relying on potentially vulnerable site ATE to monitor the path integrity/
availability. Local site monitoring may be used in addition to end to end monitoring to provide early warning of a
failure, or as a means of assisting with identifying the location of a fault.
Local site monitoring may only confirm that there is a line voltage present at the point of network connection on
a PSTN line, for example, or that the radio signal to the nearest GSM base station is present. Whereas end to
end polling or background checking ensures the entire transmission path between the alarm receiving centre
and secure premises transceiver is functioning.
•
Are key aspects of ATE fitting instructions and ATS configuration parameters suitably drawn to
installers' attention?
Supplied fitting instructions are assessed during the evaluation test programme to ensure they contain the
information to correctly install the ATE. It is a requirement of the LPCB approval scheme that any installer
configurable parameters must be included in the fitting instruction or similar documentation.
•
Is sufficient advice given to installers on identifying and protecting site network equipment?
ANNEX C of LPS 1277 provides good practice guidance to installers, and includes advice on identifying and
protecting of site network equipment.
•
What protocols exist to ensure ATE/ATSs with viable performance parameters are:
- provided in a recognised ('grade') default configuration?
- suitably authorised by end users if set up by installers differently to the default, or later changed
from it?
LPCB approval requires any system configurable parameters* (i.e. those usually implemented by the alarm
receiving centre) required for compliance with the designated enhanced performance levels of LPS 1277, to
be defined. The details shall be made available on request to facilitate checking of the system configuration.
* Some ATS require configuration settings be made to the application software which may be located at the
alarm receiving centre. These settings define the reporting times and other key functions of the ATS and may
be in addition to the configuration settings made at the secure premises transceiver (SPT) by the installer.
Guidance provided in ANNEX C of LPS 1277 reminds the installing company of its obligation to advise the end
user that, where the performance of the secure premises transceiver is capable of being changed after
installation, such changes will be confirmed in writing by the customer; with the relevant notification stating
that any such change is compatible with the risk assessment and/or the requirements of any interested party,
for example an insurer.
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•
What protocols exist to ensure that ATS messages are immediately passed to the ARC AE, and thus
an operator for action?
Such protocols are normally a function of the management procedures in place at the ARC. However, LPS
1277 requires that any message holding feature as supplied is disabled by default, with a reminder in ANNEX
C that enabling message holding is by written agreement involving all associated parties.
In summary, LPS 1277 has built on the basic requirements of the EN standards with the following:
•
The detection of faults on transmission paths determined by end to end polling/background checking
•
A 10 minute reporting time classification via 'enhanced' ATS 4Plus.
•
'Stepped-up' reporting of the secondary transmission path when the primary has been lost is to be
operated for at least 96 hours.
•
Confirmation of the time to detect a fault in the event of catastrophic failure – for example a fault in the
power supply circuitry of the secure premise transceiver, where communication over both the primary
and secondary paths immediately stops.
•
The recognition of duplicate transmission paths.
•
Testing performed over a 'live' network to confirm performance in 'real world' conditions. The parameters
derived from these tests are displayed in the Red Book listing, giving the specifier information about the
actual performance that can be achieved.
The LPS also provides clear 'good practice' installation guidance in ANNEX C, supporting the information given in
the BS EN 50131 series of standards.
LPS 1277 has added clarity to the UK's alarm signalling requirements, but its core criteria remain deeply rooted
in BS EN 50131 and BS EN 50136. It can be argued that the scheme both supports the use of European
Standards and encourages their continued development.
The LPCB approval scheme ensures continued compliance with the standards through regular checking of the
approved product and auditing of the quality management systems at its place of manufacture.
Being better informed about ATS requirements, coupled with the use of a recognised scheme for objective
assessment, will help specifiers to select ATS in general – and specifically to ensure their performance and
reliability is appropriately matched to the (risk assessed) nature of the alarm systems with which they are used.
To download a free copy of the LPS 1277 standard and view Red Book listings visit the Red Book website
www.redbooklive.com
For more information please contact staplesm@bre.co.uk
Note
LPCB stands for Loss Prevention Certification Board – a certification brand of BRE Global Limited (formerly
known as BRE Certification Limited), which is part of the BRE Group and owned by the BRE Trust (a registered
charity that uses profits made by the BRE Group to fund research and education programmes designed to
improve the built environment).
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