A connection to our 24 hour Alarm Receiving Centre (ARC) means that in the event of a confirmed alarm, police and keyholders will be summoned. A range of alarm signalling methods are available, from the single path digital communicator to BT Redcare which provides continual monitoring to identify interference such as line cutting, and DualCom or BT Redcare GSM high security signalling, utilizing two diverse signalling paths.

Most commercial installations comprise of a number of different detection devices. These may include movement detectors, glass break detectors, shock sensors, and door contacts. We can also install portable or fixed personal attack devices allowing you to activate the alarm at any time. The detection devices are connected to the control equipment. The type of control equipment is dependent on the number of detectors you require..


Digital Communicator

The digital communicator utilises your existing telephone line or a separate telephone line to send signals to the Alarm Receiving Centre (ARC). The communicator can send up to eight different types of signal depending on the situation, such as a personal attack signal in the event of a personal attack switch being activated. The ARC will then take the appropriate action for the signal received. The digital communicator provides local identification of a failure with the telephone line, but it does not provide indication of this at the ARC.


DigiPlus® has been developed as a solution to the uncertainty surrounding BT's Next Generation Network (NGN), the 21st Century Network (21CN). 21CN was scheduled to upgrade the whole UK PSTN network over the next five years. This strategy was recently changed to focus on upgrading exchanges as and when the new technology is required or the legacy equipment within the exchange has reached the end of its economic life.

Since the announcement that the 21CN roll-out will happen on a more spontaneous basis, Installers should be alert for Telephone exchange upgrades in their region. Failure to do so may leave existing signalling devices that rely on copper telephone lines, such as digital communicators susceptible to malfunction with the added cost caused by additional phone line charging from non-freefone numbers. 

DigiPlus® is a small device that was developed in conjunction with Vodafone that fits between any existing digital communicator and the telephone line providing an improved and robust signalling solution. DigiPlus® is guaranteed to make all existing digital communicators fully compatible with BT's 21CN. DigiPlus® will operate on both the old and new networks, providing the Installer with peace of mind that if the exchange is upgraded, the Alarm system will still signal through to Southern or Northern Monitoring's ARCs.

The DualCom GPRS Range

CSL have pioneered a single hardware platform which fits every grade of security risk, right the way from Grade 2, 3 and 4 Security installations to the highest specification of Fire signalling grades. The price of the product has been matched to the grade so that if you are installing for a Grade 2 specification you are not paying Grade 4 prices.

[ Download Brochure ]

DualCom DigiAir®

Eliminate call costs and phone lines with brand new DualCom DigiAir® 

DualCom DigiAir® is a groundbreaking wireless digital communicator embracing the concept of a digi and combining it with the multi-network WorldSIM®. DigiAir® simply utilises all mobile networks via a radio path instead of using a telephone line like a Digi, removing all call costs. 

Designed for maximum panel compatibility 
Small enough to fit into any existing panel 
Dial Capture provided as standard 
Fast Format, Contact ID & extended SIA 
Gemini Insight® compatible for instant access to performance stats and unit management 
Unaffected by Next Generation Networks using fibre technology 
Patented Technology - GB24658

[ Download Brochure ]

British Telecom Classic Redcare

BT Redcare is an alarm monitoring system that will signal upon activation or when the telephone line has been cut. An additional benefit of BT Redcare is that it can be connected to an existing speech telephone line, thus reducing the cost of monitoring.

A low frequency signal is transmitted by the BT Redcare equipment within the alarm control panel down a conventional telephone line to the local BT exchange. If the line is cut the low frequency signal will not be received at the exchange. Line cuts can thus be detected and the ARC alerted. A second high frequency polling signal is sent from the exchange to the BT Redcare equipment. On receipt of this message the BT Redcare equipment will transmit back a response. This two way messaging ensures that the equipment cannot be substituted. The messages are encrypted and authenticated to ensure that they can not be simulated by external computer equipment. 

Whilst BT Redcare will work with a normal telephone line, faxes and modems interfere with BT Redcare signals and therefore should not be used on a BT Redcare line, unless a 'modem compatibility device' is fitted.

British Telecom Redcare GSM

Redcare GSM is the most secure alarm signalling service available on the market today. It is the only dual-signalling system that automatically provides a confirmed activation if both the landline and radio paths are attacked, regardless of which one is attacked first. Redcare GSM offers you double protection by combining Redcare's fail-safe alarm signalling technology with BT O2's radio network. It is the only dual signalling system that continuously monitors both the primary and secondary paths, making it one of only a few systems that conform to the highest level - Grade 4 - of European Standard 50131/1.

If you want the best form of dual-signalling, then Redcare GSM is for you. BT Redcare's contingency signalling is also ideal if your insurance company requires your alarm system to transmit 'confirmation' signals after a line cut.

BT Redcare Secure

24/7 support

A team of skilled BT Redcare technicians is on hand 24 hours a day, 365 days a year, so you can always rely on our total support.

3 in 1

There are three great product variants to the new BT Redcare Secure range, but we won’t tie you down to just one. Whether you choose Secure 2, Secure 3 or Secure IP you will be able to move between all three options should your business need to.

21CN compliant 

BT Redcare Secure is a suite of security solutions that looks to the future, not to the past. They meet the highest industry security requirements (AC PO and British/ European standards) and as with all Redcare products, the new portfolio is 21st Century Network compliant meaning your product will continue to work in the 21CN environment.

No call charges/hidden costs 

When it comes to cost, we think it’s important that what you see is what you get.We have made a point of having no call charges – pretty significant when you think it could save you between £30 – £50 a year on your phone bill.

Future proofed 

By choosing a BT Redcare Secure solution you will be securing your business for the future, as well as the present. Should your business risk or future technology change, your Secure solution can be adapted to meet your new requirements.

Value for money 

A feature-rich security solution that gives you peace of mind at a price that won’t break the bank.

Dual signalling 

BT Redcare’s dual signaling approach allows a ‘confirmed activation’ to be sent to your Alarm Receiving Centre, even if your telephone line has been attacked

NSS Security Solutions

NSS Security Solutions Ltd

NSS is registered with the SSAIB, a leading certification body for organisations providing security systems and services, fire detection and alarm systems.

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NSS Security Solutions Ltd

Registered Office:
14 Harelands
Courtyard Offices
Moor Road
North Yorkshire
DL10 5NY

Mr N Simpson

Company Reg. No.