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If the unverified alarm or sequentially verified alarm is generated by a tamper condition, this should be separately identified, as required by EN 50131-1, for l&HAS grades 3 and 4.

NOTE 2 The requirement of EN 50131-1 (Table 8) for an “intruder alarm” indication is met by the “unverified alarm.”

The processing requirements and timing performance specified in EN 50131-1:2006, 8.4 and 8.9, should apply to each alarm condition individually.

The use of a dual path alarm transmission system should be considered in order to maximize the ability to transmit a second signal to the ARC. (See also Clause 11.)

The generation of a verified intruder alarm should not be permitted whilst the IAS is unset.

All IAS including alarm verification techniques should either

• notify all set I unset events to the ARC,

• or

• notify “abort" to the ARC to indicate to that an authorised user has performed an action to report that the previously notified alarm should be cancelled.

The generation of a verified hold-up alarm should not be permitted whilst the HAS (or HAS portion of an l&HAS) is unset.

Consideration should be given to the use of an alarm reporting format capable of providing detailed information about alarms to the ARC (EXAMPLE: identification of detector(s)).

The following additional signals or messages, additional to £N 50131-1:2006, Table8, should be processed and notified to an ARC by l&HAS using sequential alarm verification:

• unverified alarm;

• sequentially verified alarm;

• automatic reinstatement;

• automatic reinstatement with detector inhibited.

If the unverified or sequentially verified alarm is generated by a tamper condition, the tamper condition should be separately notified, as required by EN 50131-1:2006, Table 8, for l&HAS grades 3 and 4.

NOTE 1 The requirement of EN 50131-1:2006, Table 8, for an “intruder alarm" signal or message is met by the “unverified alarm."

NOTE 2 “Automatic reinstatement” may be notified by restore of the unverified alarm notification signal or message.

The event recording requirements of EN 50131-1:2006, 8.10 should be met by an l&HAS using alarm verification.

The following events, additional to those shown in EN 50131-1:2006, Table 22 and EN 50131-3:2009 Table 11, should be recorded by l&HAS using sequential alarm verification:

• unverified alarm;

• sequentially verified alarm;

• automatic reinstatement;

• detector inhibited at automatic reinstatement (including, at grades 3 and 4, identification of detector).

NOTE 1 The recording of events is optional at grade 1

NOTE 2 The requirement of EN 50131-1:2006, Table 22, for an “intruder alarm" event is met by the "unverified alarm."

If an unverified alarm or sequentially verified alarm is generated by a tamper condition, this should be identified accordingly, as required by EN 50131-1:2006, Table 22.

NOTE 3 For a sequentially verified l&HAS, the final paragraph of EN 50131-1:2006, 8.10 may be read as applicable to each alarm verification period; the number of events recorded could therefore exceed ten during a single set period.

Reference EN 50131-1:2006, Table 6, the permitted access level to restore an unverified alarm should be as specified for “hold-up,” “intruder” or “tamper” as applicable.

Restoration of an l&HAS following a sequentially verified alarm should be by access level 2 or 3 user, or may be restricted to access level 3.

NOTE If one or both of the alarms resulting in a verified alarm is a tamper, the minimum access level specified in EN 50131-1:2006, Table 6 applies.

Documentation for l&HAS including alarm verification should comply with CLC/TS 50131-7:2010, Annex G with the following additional information

• details of alarm verification method(s) used including, where applicable, details of parts of the supervised premises in which verification is applied, itemising each method of alarm verification separately where applicable;

• cautions for the client with regard to response limitations imposed by the system design choices made;

• the location of each HUA device, which information should be available to the ARC (see 8.1.1).

Verification of hold-up alarms should be applied only where considered necessary or is specified (EXAMPLE: by response authority)

It is recommended that a telephone call-back procedure should be available for the ARC to follow if the results of any method of alarm verification are inconclusive. Where this method is used, only correct use of an identity code or password should be acceptable to cancel response to a hold-up alarm.

NOTE A single identification code / password may be shared by all users at the supervised premises.

7 Sequential verification of intruder alarms

I

AS restore

Alarm

= verified alarm

AS unset

Alarm

= unverified alarm

AS set

Events:

Verification time

Notification to ARC:

SET

UNVERIFIED

ALARM

VERIFIED UNSET RESTORE

ALARM

1. - Time line of completed sequentially verified alarm sequence

Events:

IAS set

Alarm = unverified alarm

Verification time

Ready for additional events

Notification _QPT to ARC:

UNVERIFIED

ALARM

REINSTATEMENT

2. - Time line of unverified alarm sequence

These recommendations are additional to the requirements of EN 50131-1.

The following recommendations are applicable to all IAS using sequential alarm verification, at all security grades (except where stated).

An alarm should be designated as sequentially verified when a minimum of two of the conditions identified in Table 1 are present in any combination.

Table 1 - Types of alarm permitted to contribute to a sequentially verified intruder alarm

The combination of a tamper alarm or ATS path fault with a hold-up alarm should be interpreted as a verified hold-up alarm (see 8.1.2).

To be designated as a sequentially verified alarm, the sequential alarm should be generated within a maximum of 60 min after the unverified alarm.

In the event that a sequentially verified alarm does not take place within this time, automatic reinstatement of the IAS should take place (see 7.2.4).

NOTE The time intervals when an ATS path fault is valid as one of the alarm verification conditions (see Table 1) are specified in Clause 11.

If a sequentially verified alarm has not been notified before the expiry of alarm verification time, the l&HAS should remain in the set state, but be able to respond to detection of a new unverified alarm.

In the event that the detector initiating an unverified alarm remains in alarm at the time of automatic reinstatement, the detector should be automatically inhibited and should remain inhibited until the l&HAS is manually restored (see 6.6).

Automatic reinstatement should be notified to the ARC, including, if applicable, warning that a detector has been inhibited (see 6.4)

If a detector that would normally start a timed entry procedure is inhibited, there should be an alternative means of starting the procedure.

NOTE This may be performed by design of the l&HAS or by the CIE automatically changing the operation of other detectors forming part of the entry/exit route.

These recommendations are additional to those in CLC/TS 50131-7.

Design of the l&HAS should ensure that alarm verification capability is commensurate with the risk.

The risk assessment should ensure that detectors are sited such that triggering of two detectors provides a high probability of a genuine intrusion, in particular:

1. siting of detectors using the same technology should be restricted, in order that their coverage does not overlap,.

2. detectors of the same technology should be sited such that a single environmental effect would not result in activation of both detectors (see also CLC/TS 50131-7:2010, Annex C),

3. an alarm generated by a single “single-output combined detector” should not constitute a sequentially verified alarm,

4. if “multi-combined detectors” (See A.3) are used to generate a sequentially verified alarm, care should be taken so that a single environmental stimulus could not result in a verified alarm,

5. configuration of a single detector to require two or more activations in a nominated period (or a single activation lasting for a nominated period) before an alarm is presented to the IAS should not permit an alarm to be considered as verified,

6. a second activation of the SAME detector should not be notified as a sequentially verified alarm unless the activations are an intrusion event and a tamper event, in either order.

Consideration should be given to providing means for a user responding to an unverified alarm to be made aware of the fact that an alarm has subsequently become verified, before entering the premises. (EXAMPLE: indication at point of entry, strobe fixed to WD activated by verified alarm, etc.)

See Clause 11.

ARC responses are specified in EN 50518-3.

8. Sequential verification of hold-up alarms

   1. Recommendations for system requirements

      1. General

These recommendations are additional to the requirements of EN 50131-1.

If sequential verification of hold-up alarms is used, the ATS should permit transmission of separate signals or messages from different hold-up alarm devices or the different outputs of a multi-action hold-up device.

Zoning of hold-up devices should be optimized for the most timely and effective response in accordance with EN 50131-1:2006, Table 7, Note b. Thus zoning information should be passed to the ARC.

The sequential alarm sequence of a hold-up alarm combined with a second hold-up alarm, an ATS path fault, an intrusion alarm or a tamper alarm should be interpreted as a verified hold-up alarm.

Two hold-up alarms being designated as a verified hold-up alarm may originate from two separate devices, or from a single multi-action hold-up device.

The alarm verification time for hold-up alarms should be within a maximum of 24 h of the unverified alarm.

In the event that a sequentially verified hold-up alarm does not take place within this time, automatic reinstatement of the HAS should take place.

NOTE The time intervals when an ATS path fault is valid as one of the alarm verification conditions (see Table 1) are specified in Clause 11.

These recommendations are additional to those in CLC/TS 50131-7.

Design of the l&HAS should ensure that alarm verification capability is commensurate with the risk, and that the most appropriate type of hold-up device (or multi-action hold-up device) is used.

See Clause 11.

ARC responses are specified in EN 50518-3.

8. Audible alarm verification

   1. System design factors

      1. General

These recommendations are additional to the requirements of EN 50131-1.

Precautions should be taken to prevent breaches of privacy legislation.

Consideration should be given to supplementing audible alarm verification by sequential alarm verification (see also Clause 4).

In order to provide means of audible alarm verification there should be means to:

1. store at least 10 s of audio immediately prior to an alarm, ready for transmission to ARC on demand,

Where detection is by AMD, this may be reduced to 1 s.

2. store audio following an alarm at least until the audio link is established with the ARC,

3. transmit live audio to the ARC on demand.

Where the l&HAS is divided into sub-systems, it should be possible to transmit audio information relevant only to a sub-system of the l&HAS that is set at the time of the activation.

It should be possible to transmit audio information only following an alarm or as part of maintenance or other procedures with the agreement of the client.

In order to prevent interference with audio information being transmitted to the ARC, notification to warning devices should be delayed until an alarm is designated as verified by the ARC or inhibited, as permitted by EN 50131-1:2006, 8.6.

NOTE Audible alarm verification of the entry route may not be appropriate.

These recommendations are additional to those in CLC/TS 50131-7.

All detectors and hold-up devices for which alarm verification is required, as well as CIE and SPT, should be located within the area of coverage of an ALD.

ALDs should be sited to avoid noise sources that could interfere with the ARC operator’s ability to listen to audio information transmitted from site.

The area of coverage of an ALD should be greater than the area of coverage of the associated detector(s).

In the case of audible verification of hold-up alarms, the area of coverage of an ALD should be tailored to the threat which may be present. The area of coverage may thus differ from the location of the HUA device.

Where the l&HAS is divided into sub-systems, care should be taken to ensure that audio information from devices within a sub-system that is set cannot transmit audio from another sub-system that is not set.

ARC responses are specified in EN 50518-3.

8. Visual alarm verification

   1. System design factors

      1. General

These recommendations are additional to the requirements of EN 50131-1 and EN 50132-1.

Precautions should be taken to prevent breaches of privacy legislation.

Consideration should be given to supplementing visual alarm verification by sequential alarm verification (see Clause 4).

In order to provide means of visual alarm verification there should be means to transmit at least 4 images to the ARC - one originating within one second prior to the activation, one at the time of the alarm activation (or the activation of the VMD), plus two additional images within 5 s of the activation.

Where the l&HAS is divided into sub-systems, it should be possible to transmit visual information relevant only to a sub-system of the l&HAS that is set at the time of the activation.

It should be possible to transmit visual information only following an alarm or as part of maintenance or other procedures with the agreement of the client.

These recommendations are additional to those in CLC/TS 50131-7.

All relevant detectors and hold-up devices for which alarm verification is required, as well as CIE and SPT, should be located within the area of coverage of an imaging device.

The illumination of the area of coverage of an imaging device should be adequate to meet the selected requirement of EN 50132-7:2012, 6.7 such that visual verification of an alarm event is possible.

Imaging devices should be sited to avoid light sources that could interfere with the ARC operator's ability to view information transmitted from site. In particular, strobing devices attached to WDs should be sited so as to avoid interfering with visual information or be inhibited until the ARC has designated an alarm as verified.

The area of coverage of an imaging device should be greater than the area of coverage of the associated detector.

In the case of visual verification of hold-up alarms, the area of coverage of an imaging device should be tailored to the threat which may be present.

NOTE The area of coverage may thus differ from the location of the HUA device.

Where the l&HAS is divided into sub-systems, care should be taken to ensure that visual information from devices within a sub-system that is set cannot transmit images including part of another sub­system that is not set.

ARC responses are specified in EN 50518-3

8. .ATS faults

   1. System design factors

      1. General

These recommendations are additional to those included in EN 50131-1 and EN 50136-1.

ATS path faults may contribute to a verified alarm as follows:

1. an ATS path fault followed by an intrusion, tamper or hold-up alarm within the same set period;

2. an intrusion, tamper or hold-up alarm signal or message followed by an ATS path fault during the

same set period;

3. two ATS path faults, relevant to different paths, during the same set period. The two paths should be of different technologies (see EN 50518-3:2013, 5.7); typically land-line and wireless.

The time permitted during the set period may be varied independently for intrusion and hold-up alarms.

The sequential alarm sequence of a hold-up alarm combined with an ATS path fault should be interpreted as a verified hold-up alarm (see 8.1.2).

These recommendations are additional to those included in CLC/TS 50131-7 and the requirements of EN 50136-1.

NOTE 1 The provision of a dual-path ATS does not, of itself, constitute a method of alarm verification.

NOTE 2 Consideration should be given to the use of dual-path ATS to prevent notification of alarm verification being disabled by a single path fault.

ARC responses are specified in EN 50518-3

.Annex A
(informative)

Equipment specifications

A.1 General

The recommendations of this annex should be applied when components are intended to permit l&HAS to perform alarm verification.

Equipment need not be designed to meet ALL recommendations of this annex, but the manufacturer’s documentation should identify all recommendations implemented, along with details of the optional parameters provided.