In a non-addressable system the input devices work a bit like a switch. When they are activated they "Turn On" the panel, which in turn will "Turn On" the bells or sounders. The input devices in a particular area are connected to one circuit, called a zone, so that an indicator on the control panel will light to show which zone has been activated. The sounders are usually wired on separate sounder circuits. non-addressable Systems are particularly effective in smaller premises such as offices and shops. A newer type has the sounders on the zone circuits. These are referred to as "Two Wire" systems. Two wire systems are particularly useful where there are a lot of devices close together such as a house or small hotel.

In an Analogue Addressable Systems all the devices are wired on ring circuits called "loops". The devices electronically carry on a dialogue with the controls. The input devices continuously send back there "analogue value". The analogue value corresponds to the amount of smoke present for a smoke detector and the temperature for a heat detector. The controls are "Intelligent" and can decide when a device has reached its "alarm" value. The controls can instruct some or all of the output devices to operate. The controls can be "Programmed" to operate certain outputs according to which input device has been operated. These systems are particularly useful in larger premises such as Hospitals, Shopping Malls and factory / office complexes.

Fire Alarm Systems that use radio work a bit like analogue systems without the wiring. When the input devises are not in an alarm condition they periodically call in to the control panel with their "analogue value". The analogue value corresponds to the amount of smoke present for a smoke detector and the temperature for a heat detector. As the analogue value approaches the alarm value they call in more frequently. The controls are "Intelligent". When a device has reached its "alarm" value the controls instruct some or all of the output devices to operate. The controls can be "Programmed" to operate certain outputs according to which input device has been operated. These systems are particularly useful in larger premises where wires can't be used such as listed buildings, distributed sites with no direct path for wiring between buildings, temporary buildings and marquees.

It is frequently possible to convert old non-addressable systems to Analogue. This is particularly attractive where large older premises are being updated or premises are being extended.

Most Analogue system can have radio "Extensions" for those "Hard to get at places" or are designed to mix Radio and Hard Wired Technology.

• How does a fire alarm system work?
• What types of system are there?
• What Standard Should it be Engineered to?
• What Type of System do you need?
• How can you be sure that MK Fire is the right company to install you system?