5
Fire detection and evacuation solutions that save lives.
MAN3070
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5
The XPander Wireless Range
Wireless system
Analogue addressable fire alarm systems have been in use for
many years and have proven their worth in countless
installations. Ampac Technologies wired systems comprises not
only detectors and manual call points but also interfaces,
sounders, beacons and special detectors such as beam and
flame detectors.
Wireless systems are often installed in buildings where wiring
presents a challenge, most often because the fabric of the
building or its design will be negatively affected by the use of
cables. It is sometimes very difficult to introduce cable runs into
buildings which were not designed for the modern age. It may
also be that a collection of buildings, such as an open air
museum, requires fire protection but is not suitable for normal
wired systems. It is for buildings of this kind that XPander has
been developed. XPander is a wireless extension to a loop
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wired
XP95 or Discovery detection and alarm system.
XPander is a system in which individual detectors, call points
and alarm devices communicate with the XP95 addressable loop
by radio signals. The interfaces are connected to the loop in the
same way as any other interface, such as an Input/Output Unit.
Every XPander device is assigned an address and this address is
recognised by the control panel in the same way as is the
address of any device connected directly to the loop wiring.
It should be noted that not all installations can be extended by
using XPander and it is essential that a site survey is conducted
to check whether XPander can be installed or not.
Polling
XPander detectors and alarm devices are polled in the same way
as devices connected directly to the loop. They respond in
exactly the same way and provide the same categories of
information.
Address Mechanism
XPander detectors are addressed by means of the XPERT card
familiar to users of XP95 and Discovery. The XPander XPERT
card is specifically d esigned f or X pander p roducts having
profiled address PIPs for ease of installation.
Radio Communications
Fire detection systems are life
-
saving systems and must,
therefore, be highly reliable in use. Radio communications have
been developed to a point where high reliability can be
guaranteed, provided that the rules for the design of radio
systems and installation are carefully observed. Radio
communication technology in the detection has matured to the
point where a standard has been drawn up as part of the
AS7240 family of standards for components of a fire detection
system. The standard is AS7240
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25
Frequency
The frequency used by XPander is 915MHz.
Signal Integrity
It is of prime importance that the radio signal retain its integrity
even if minor changes, such as the rearrangement of furniture, are
made to the environment in which XPander is installed. Hence
“
extra strength
”
signals are used so that the signals are received
clearly even if there is some attenuation. XPander Diversity has
multiple aerials positioned at different angles within the loop
interface. The interface is able to intelligently and dynamically select
the radio communication path with the fewest destructive
reflections, and with the best signal strength. This ensures greater
signal integrity and improved range in complex indoor
environments.
Interference
It is of equal importance that there be no interference to the device
from signals emanating from other sources, such as police or
ambulance radio systems.
To help eliminate interference the XPander signal is a narrow band
signal with an additional coding. With the inclusion of the dual band
signalling the danger of interference has been reduced to a point of
being negligible.
Battery Monitoring
Devices in the XPander range are powered by batteries. There are
two battery packs, with current being drawn alternatively from
each. It is essential that the state of the batteries be known and the
following three states have been defined:
State
Condition of batteries
Normal
Good working order
Fault
Batteries need to be changed
Missing
Battery voltage very low or bat-
tery pack incorrectly fitted.
For the
“
Fault
”
state a warning is sent 30 days
and for the state
“
Missing
”
a warning is sent 7
days before battery failure.
Note: when changing batteries both packs
should be replaced
