Page 287 - Advanced Course

KNX ADVANCED COURSE

3.2.2 ‘Audio over IP’ system controllable via KNX
The following example shows an ‘Audio over IP’ system, which communicates with KNX
via a special KNX to IP gateway.

Audio source 5
Audio source 1 Audio source 2 …
(e.g. CD player 1) (e.g. Radio Tuner) (e.g. CD Player 2)

Module 1 IP Audio Central Unit
Speaker

Network Switch IP

Speaker
Module 2 IP
… IP

KNX/IP Interface
Speaker Other IP devices (PC,
Module IP tablets, smart phones) KNX BCU
254

Ethernet

Analog

KNX

Figure 10 - An ‘Audio via IP’ system controllable via KNX
The audio central unit consists of two segments. The first segment foresees analog
inputs, to which all audio sources are connected. The second segment consists of a
network interface (TCP/IP) that plays also the role of the analog-to-digital converter.
Thus, the analog signal from the audio sources is converted to digital and is transferred to
the speakers via the IP network. The speakers contain also a network interface, which
converts the digital signal from the network to analog in order to be reproduced on the
speakers.
The communication with the bus is realized with a specific KNX/IP gateway, which is
configured to transfer data from KNX to the audio system and vice versa. That gateway is
both a KNX addressable subscriber as well as and IP network addressable device.
It is important to be mentioned that the term ‘multiroom audio controller’ is used by most
of the KNX manufacturers producing devices for audio control, either their are equipped
with a KNX BCU, or KNX/IP interface.

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