Bosch PRAESENSA, Installation Manual

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16 en | System introduction PRAESENSA
2019.11 | V1.00 | Installation manual Bosch Security Systems B.V.
properties of air change with altitude, decreasing its insulator capabilities. PRAESENSA
uses effective heat sinking and significantly increased creepage and clearance distances
to maintain safety ratings.
– All system devices use dual Ethernet ports, supporting RSTP, to recover automatically
from a broken network link.
– The multifunction power supply offers battery backup facilities to be insensitive to mains
failures.
– Amplifiers have an integrated spare amplifier channel to take over from a failing channel
automatically. They also have double power supplies built in, working in tandem to
minimize stress on components, while each one is capable of supplying full power to the
amplifier if one section would fail.
– The amplifiers have two loudspeaker outputs per channel, group A and B, separately
supervised and protected, to support connection of interleaving loudspeaker strings in
the same zone, so a shorted or interrupted loudspeaker line will not mute that zone
completely.
Optimized user experience
– The PRAESENSA call stations provide a combination of a large touch screen LCD with
mechanical buttons and LED indicators. Access to system functions and areas can be
configured per call station, to provide exactly the functions the operator needs, not more,
not less. The user interface has been developed in cooperation with real users and
addresses their needs, but also their discomforts when making calls to zones they can’t
see or hear, or adjusting the volume of background music in these areas.
– Functions are easily selected from the touch screen, and zones are easily selected via
keypad keys with LEDs giving immediate feedback on the actual status of that zone. After
starting a call, the screen shows the operator the progress of the call, indicating when to
speak after a start tone or automatic introduction message has finished, and showing
whether the call was successfully completed in all destinations.
Fully-featured as standard
– PRAESENSA is an advanced system for Public Address and Voice Alarm purposes. The
system consists of a limited range of hardware devices in combination with software to
create the required functions. Because the hardware devices are very complete and
flexible to use, only a few different devices are sufficient to create a system. For instance,
all call stations and amplifiers have a built-in DSP for sound processing, the amplifiers
have flexible output power per channel and a built‑in spare channel, the power supply has
a built‑in battery charger, and so on. No need for separate add‑ons.
– System functions are software based and regularly updates become available to extend
the set of capabilities.
Scalable and flexible
– PRAESENSA is an extremely scalable and flexible system. All devices are network
connected and offer loop‑through connectivity for easy system expansion and RSTP to
create a fail-safe network loop. System devices can be decentralized and their redundant
loop wiring often allows for cheap non fire‑resistant network cables to be used.
– PRAESENSA uses dynamic channel allocation. Because devices do not use static routing,
amplifiers and call stations do not have a permanent audio connection to the system
controller. That approach would limit the number of devices, since an 8‑channel amplifier
would at least need 8 connections, 100 amplifiers would need 800 connections to be
independent. Instead, PRAESENSA uses dynamic OMNEO connections that are generated
on the fly when needed and freed up after use. Dynamic streams occupy the least
bandwidth; if there is no audio transport going on, the channels are simply not there.