DD:243 and Confirmed Alarm Signalling

DD:243 is a Code of Practice for the installation and configuration of intruder alarm systems designed to generate confirmed alarms. This Code of Practice supplements PD6662 and EN50131.DD:243 was originally introduced in 2002 to tackle two main areas :

Its Purpose

• To further reduce false alarms during setting/ unsetting
• Improving the operation of alarm confirmation technology

DD:243 applies to all new systems incorporating confirmed alarm technology and to existing systems, which have been removed from Police response and are being upgraded to confirmed alarm technology to re-gain response.

Note: All new Police calling systems in England, Wales and Northern Ireland must be fitted with alarm confirmation technology. Alarm confirmation is recommended for new systems in Scotland but is not mandatory.

How does Draft for Development 243 (DD243) affect your intruder alarm system?

System Un-setting

Most older systems are unset at a keypad during an entry time that starts as you enter the door to your premises. If you already use this method, under DD:243 all alarm confirmation would have to be turned off when the door opens, however, this means that a break-in through the entry door cannot be passed for police response.

Abbion Fire and Security Systems recommend Option (d) below.

DD:243 allows five un-setting methods:

a) System un-set by unlocking the initial entry door.
b) Unlocking the entry door disables all confirmation then system un-set internally (as present).
c) Opening the initial entry door disables all confirmation (not acceptable to most insurers).
d) System is unset using an electronic token for example a proximity fob, smart key or infra-red/radio fob 
e) Un-setting carried out in conjunction with the Alarm Receiving Centre.

System Setting

Abbion Fire and Security Systems recommend Option D below.

DD243 allows six methods to complete the setting of your system:

a) Key operated shunt lock on final exit door
b) Push button outside the premises
c) Door contact on the final exit door
d) Electronic token
e) In conjunction with the alarm receiving centre
f) For systems installed to the new European Standards, EN 50131, other means (future).

For both un-setting and setting your system Abbion Fire and Security Systems recommends option (d) - using a proximity fob with a system keypad incorporating a proximity reader located just inside the entry/exit door. This provides a simple operation for keyholders and eliminates many alarms caused by incorrect PINs etc.

DD:243 also recommends that additional internal audible indicators and keypads incorporating token readers are located in the premises to allow the system/areas to be unset locally and avoid inadvertent setting while someone is in the building.

Alarm Confirmation Technology - What is it??

Alarm confirmation can be in the form of:

  • Sequential Verification
  • Audible Verification
  • Visual Verification

Sequential Verification

With sequential confirmation, the alarm system is designed in such a way that it gives separate alarm indications from different detection devices, one after another within a time window of 30-60 minutes (confirmation time), the second confirming that the first was not caused by a fault or spurious event, e.g. falling poster.

Detectors must be configured as follows:

ALLOWED sequential combinations
• 2 detectors of different technologies i.e. break glass & movement
• 2 detectors, same technology with minimal or non-overlapping areas
• 2 dual technology movement detectors or 1 passive infra-red and 1 dual technology movement detector; coverage may overlap but detectors must be located some distance apart
• 1 alarm and 1 tamper
• 1 communications line fault and 1 alarm or tamper
• Faults on 2 separate communications paths

NOT ALLOWED sequential combinations
• 2 single technology movement detectors overlapping
• 1 double knock combination i.e. 2 activations from 1 detector
• 2 vibration or break glass detectors overlapping
• 2 foil on glass on same door/window
• 2 switches on same door
• 2 atmospheric detectors
• 2 audio detectors or video motion detectors

While un-setting, all confirmation is delayed until after expiry of the entry time. Any alarms received during that time are classified as unconfirmed regardless of how many are activated. If a break-in should occur through the main entrance door, following expiry of the entry time, two additional detectors off the entry route would be required to activate to provide a confirmed alarm.
If at the end of the confirmation time window a second activation is not received the alarm system may be configured to auto re-arm. If a further activation is then received, after this period and after re-arming, the confirmation time re-starts.
When the system re-arms and if a detector is still in alarm i.e. a door is open it will be by-passed (ignored) and a warning will be sent to our Alarm Receiving Centre.  The Alarm Receiving Centre can call the keyholder and warn them the premises are not fully protected.

Audible Verification

Where this is employed, the first detection will open up an audio link so that trained operators at the Alarm Receiving Centre can listen to the premises and judge if the alarm is genuine. The call will then be passed to the Police where appropriate.

Visual Verification

With visual confirmation, the first detection opens up a CCTV path so staff at the Alarm Receiving Centre can view key areas within the site, and judge if the alarm is genuine. The call will then be passed to the Police where appropriate.
If used in addition to sequential verification there are no significant changes to the operation of Audio or Visual confirmation systemsAbbion Fire and Security Systems would always recommend they are used in conjunction with Sequential Confirmation.

Unconfirmed Signalling

This is a single signal and will initiate a Keyholder response only. Unless it is a system in Scotland that has not lost police response or that has been installed prior to October 2001 in England, Wales or Northern Ireland when it may receive a police response, provided the system has not exceeded the false alarm threshold.

Confirmed Signalling

This is the preferred solution and will ensure the Police receive a confirmed alarm signal, even if the telephone line is cut. In this case a line cut signal followed by a radio (GSM) second signal will initiate police response.



                                                                                                         "Installing Confidence....Maintaining Quality"                                                                                                                  

                                      Areas Covered: Cardiff, Newport, Swansea, Bristol, Rhondda Cynon Taff, Torfaen, Monmouth, South Wales, West Wales, West of England