Basic Information; How An Intrusion Alarm System Is Made; The Simplest System; Wired, Radio, And Bus - Urmet 1068 Série Mode D'emploi

1

BASIC INFORMATION

This chapter explains from which devices an intrusion alarm system is composed, their function and mutual interaction.
1.1

HOW AN INTRUSION ALARM SYSTEM IS MADE

1.1.1

The simplest system

The most elementary alarm system consists of just 3 devices: a detector, a siren, and a management device called a
control panel.
The control panel receives the information from the detector, processes it and, if necessary, makes the siren sound to
warn of danger.
Although simple, this type of system is perfectly adequate for fulfilling the use for which it was intended: generate an
alarm when an attempted intrusion is detected.
In reality alarm systems are more complex and consist of a greater number of devices, because very often the protection
needs are greater, to facilitate the use of the system by users and to integrate advanced functionalities that are not
limited to alarm only.
It is important to note that every system, regardless of its complexity or size, has only one control panel that acts as the
"brain" for the entire system.
1.1.2

Wired, radio, and bus

One of the main differences between the various types of systems is based on the technology used to connect the
devices to the control panel and between them: wire or radio (also called wireless).
Each of these two types of connections has strong points, while other characteristics make it less suitable for specific
uses.
The table below illustrates the pros and cons of both solutions.
Pros
 The system is not affected by radio shields and
within the maximum distances indicated, the control
panel can be positioned at the most convenient
point.

It is essentially immune to standard electromagnetic
disturbances: devices that emit radio frequencies or
power lines create no communication problems.
Cons

Wiring is necessary: all the detectors and signalling
devices must be connected to the control panel with
wires.

The positions of the devices are fixed because their
movement requires a new wiring, with all the
difficulties that implies.

Long installation times due to of wiring connection. If
the apartment or office does not already have a
conduit system, installation times are prolonged
because the wiring must be run under the board and
door casing to hide it, create holes in the walls and
ceilings etc.

Extensive installation
inconveniences if the premises are inhabited.
(1) Not all manufacturers have radio alarm systems that can function entirely without being connected to the electrical
utility.
DS1068-017
WIRED
times may
Table 1 - Comparison of wired and radio technologies
Pros

Requires no wiring: all communications occur via
radio and components can be positioned where it is
most convenient.

The devices can be easily moved if the need should
arise, for example if the arrangement of furniture
should change in a room protected by a volumetric
detector.

It is possible to create a system where all the
components are powered by long-life batteries, so it
is not necessary to connect the system to the
electrical power supply

Quick installation: it is sufficient to install the system
components where needed, with no need to wire
them.

Installation times are considerably shorter, so as
not, to create inconveniences in the home or
workplace.
Cons

It is sensitive to radio shielding: some materials can
affect the radio waves, impeding or making
create
communication more difficult among the various
devices.

It is more sensitive to sources of electromagnetic
disturbances (ex. electric meters, electric motors,
washing machines, refrigerators, etc.), which may
make communications among the various devices
difficult.

It is necessary for at least one radio channel to be
free (in other words, one channel with no other
systems using it).
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RADIO
(1)
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LBT20717