Fire Alarm Control Panels
Traditional fire alarm panels installed prior to 1998 were conventional zone panels. In a zoned system, fire alarm devices in a common area or floor of a facility are connected to the same alarm initiating circuit. Each zone requires its own circuit conductor. This arrangement allows alarm annunciation to be reported by areas of the building to identify which device is in alarm. Conventional panels are often used in small facilities where a few zones can provide sufficient alarm annunciation.
With the advent of microprocessors and digital electronics, addressable fire alarm control panels and devices have become more common than conventional systems for medium and large-sized facilities. They have become more cost effective in some small applications as well.
Addressable fire alarm systems use digital encoding and multiplex technology to more accurately identify alarm locations and device conditions. Each fire alarm device in a system is programmed with a unique address.
The fire alarm control panel is capable of communicating with a single address or a group of addresses depending on the functions required. The communication is often multiplexed over a common cable, sometimes referred to as the signaling line circuit (SLC). This arrangement significantly reduces the amount of cabling necessary to install the system. The communication channel allows two-way communication, thus enabling the fire alarm control panel to control as well as monitor fire alarm devices.
A significant component of addressable fire alarm system is the software programming necessary to make the system function correctly. The programming allows for flexible applications where you want to have specific control over the inputs and outputs.
The communication technologies employed in addressable systems allow for advanced features to accommodate sensitivity changes due to age and accumulation of dust prior to maintenance. These features are not available with the standard conventional system.