The NSC Sicherheitstechnik Open-area Alarm Devices are loop-powered, wall
mounted devices which are connected to any XP95 or
The range comprises sounders, beacons and sounder
beacons, all designed to fit to a common mounting
base. Details are shown in Table 1 overleaf.
The alarm devices offer:
three tones on standard devices; Apollo, Slow
Whoop and DIN – all of which comply with
two volume settings 92dB(A) and 100dB(A)
synchronisation of tones and flashes
individual & group addressing
built-in isolator (EN54 versions only)
wire-to-base for simple interchange of device
device locking facility
A nominal sound output of 100dB(A) is achieved
at a current consumption of 5mA in the case of the
sounder and 8mA for the sounder beacon.
Many control panels will be able to drive up to 20
sounders and up to 15 sounder beacons per loop on
average. The maximum number of devices that may
be connected to a particular loop should, however,
be determined by a loop loading calculation using the
Apollo Loop Calculator.
The Apollo tone version produces a pulsed alert
tone of 984Hz, 1 second off and 1 second on, and a
continuous evacuation tone of 644Hz for 0.5 seconds
followed by 984Hz for 0.5 seconds.
The volume control can be used to adjust the sound
from 100dB(A) to 92dB ±3dB(A) if required.
The sounder also offers synchronisation of continuous
and pulsed tones. This ensures the integrity of the
alert signals – tones from different sounders do not
merge into one signal that could be mistaken for an
The open-area alarm devices respond to their own
individual address set with a DIL switch.
They can also respond to a 'Group Address'
which allows multiple sounders to be controlled
A group address may be any spare
address between 112 and 126 and is selected by
means of a 4 segment DIL switch. A device under
group address control must have an individual address
between 1 and 111 otherwise a fault value of 4 is
Devices not using the group address
facility may be addressed at any address (1–126).
The alarm devices will operate only with control
equipment using the Apollo XP95 or Discovery
protocol. The features of the Open-area alarm devices
are available only when the device is connected to a
control panel with the appropriate software.
The alarm devices have a base which is fitted to the
mounting surface and wired as a 'first fix'.
Since the alarm devices are intended for use in open
areas, it is possible for more than one device to be
audible at any given point in a building. For this reason,
the operation of all may be synchronised by the
All the alarm devices can be assigned group addresses
as well as individual addresses, so that the functional
options of the sounder are identical with those of the
Sounder Control Unit part no 55000-182.
All devices are powered directly from the loop and
need no external power supply. They operate at
17–28V DC and are polarity sensitive.
TONE FREQUENCY AND VOLUME CONTROL
The alarm devices are supplied with three selectable
tones and flashes either—Apollo, Slow Whoop and DIN
or Apollo, Australia and New Zealand.