Unfortunately, we no longer supply products by NSC. Please visit the Fire Extinguishing section for alternative options.
The NSC Sicherheitstechnik Sounder Beacon Bases are comprised of a
loop-powered sounder and beacon combined with
a standard XP95/Discovery mounting base. It is used
to signal a fire alarm in enclosed areas.
The Sounder Beacon Base can be used either with
a detector fitted or with a cap for operation as a
stand-alone alarm device.
The Sounder Beacon Bases are supplied with a
built-in isolator. A version without an isolator is also
The product offers:
two volume ranges 55–75dB(A) and 75–91dB(A)
beacon flash rate of once per second
synchronisation of ‘alert’ and ‘evacuate’ tones
synchronisation of beacon flash
individual and group addressing
unique acoustic self-test
unique beacon self-test
In addition to the standard tone a version with slow
whoop tone to Dutch standard NEN2575 is available
The low volume range is useful in areas such as
hospitals where a fire alert is initially intended to
warn staff only. The sounder is set to the high range
for general use.
Synchronisation of tones ensures the integrity of
the signal—tones from different sounders do not
merge into one signal that could be mistaken for a
Group addressing is a simple method of alerting an
entire area or group of rooms without delay.
For systems requiring isolators at every point the
built-in isolator saves installation time and cost.
The acoustic self-test means that the sounder
listens to itself when it is switched on. If no sound
is detected a fault signal is transmitted when the
sounder is polled.
The beacon self test is achieved by means of an LED
monitoring circuit. If the LEDs do not draw current
when the sounder beacon base has been switched
on a fault signal is transmitted when the device is
The Sounder Beacon Base are loop powered so
needs no external power supply. It operates at
17–28V DC and is polarity-sensitive.
TONE FREQUENCY AND VOLUME CONTROL
The tone frequency of the sounders, together with
sound pressure levels, is published in a separate
document, PP2203 available from Apollo.
The Sounder Beacon Base responds to its own
individual address set with a DIL switch. It also
responds both to a group address, set by means of
a 4-segment DIL switch and to a synchronisation
address which is embedded in the unit.
Addresses 1 to 111 are used exclusively for
individual addresses; addresses 112 to 126 are used
for group addressing. Any Sounder Beacon Bases
on a loop may be freely assigned to a group. The
address for any group must be chosen from the
Addresses 112–126 may be used as individual
addresses but only if the 4-segment DIL switch is
not used ie, group addressing is disabled. If the
4-segment DIL switch were set to any number other
than the default 127, a pre-set analogue value of 4
would be transmitted to indicate a fault.
The Sounder Beacon Bases are normally polled by
the individual address. If more than one Sounder
Beacon Base is activated it is possible for the sounders
to be synchronised with each other.
It may be desirable, in alarm conditions, to switch
more than one Sounder Beacon Base simultaneously.
To enable this, devices may be controlled
as a group and given a group address which is
common to all sounder beacon bases in the group.
When a device recognises its group address, it
will process the output bits but it will not return
any data to the control panel on that address. If it
is required to confirm the status of the outputs of
devices under group address control, it is necessary
to interrogate all devices in the group at their individual
An important safety feature has been incorporated
into the Sounder Beacon Bases: when it is switched
on it tests itself by checking the actual sound output and flash operation. If no sound is detected within
5 seconds of the Sounder Beacon Bases being
switched on it will transmit an analogue value of 1 (=
sounder fault) when it is next polled. If no current is
drawn by the LEDs an analogue value of 2 (= beacon
fault) is transmitted. If neither element is operating
an analogue value of 3 (= sounder and beacon fault)
is transmitted on the next polling.
This feature can also be used during commissioning
or periodical maintenance testing. Simply activate
the sounder for at least 5 seconds and check the
control panel for a fault signal. If none is received,
the sounder beacon base is working properly.
The Sounder Beacon Bases will operate only
with control equipment using the Apollo XP95 or
protocol. The features of the Sounder
Beacon Base are available only when it is connected
to a control panel with the appropriate software.
It is possible to synchronise the sound and flash
outputs of all Sounder Beacon Bases connected
to a loop. Other alarm devices, including the
100dB Sounder, the Integrated Base Sounder,
the Intelligent Base Sounder, the Sounder Circuit
Controller and the Loop-powered Beacon, may also
This method of synchronisation depends on the
design and configuration of the control panel.
Further information should be sought from the
manufacturer of the panel.
The Sounder Beacon Base are moulded in polycarbonate
and has stainless steel contacts that accept
solid or stranded cables of up to 2.5mm˛.