Seite 11
The individual boards of the system are connected by a Netlink control data bus (RJ-11
connector).
The assignment of the microphone stations in the controller board takes place in the base
version via an automatic self selection process. Up to four or eight microphone stations
can be activated at the same time. In a further system version it is possible to administer
the microphone station management over an attached control computer.
The controller board is equipped with the two audio input connectors. The two incoming
signals are mixed together and fed to the foldback channel. This channel is transmitted
to every microphone station and the signal is audible in every single station’s
loudspeaker. This digital signal is encoded also to ensure the proposed privacy of the
entire system.
In the regular setup one of the two audio inputs is connected to one audio output of the
audio board to enable the foldback channel (mix of all microphone stations in the
stations’ loudspeakers). The second input can be used to feed an external signal (sound
signal of any media device, PC, video player, etc..).
Farther for the external control and configuration of the system a RS-232 connection is
attached to the controller board (9-pin Sub-D connector). The connection to a PC or a
media control system is made by a serial 1:1 cable.
By pressing the AUX button on the chairman microphone station a read relay on the
controller board is activated to supply a contact closure for special purposes. The contact
output (open/closed relay contact) is accessable on a Phoenix 2-pin connector. The
contact output is loadable with max. 50V and 1A.
The controller board is equipped with two transmitting and one receiving antenna
connections. These are connected by SMA patch cables with the antenna splitter board.
Via an eight-pin DIP-switch on the controller board the radio net address of the system is
determined. This radio net address is necessary, in order to be able to operate different
systems in the same environment. Also each microphone station belongs to a cewrtain
radio net address. On the microphone stations the addess is changes internally via the
programmer port.
3. Audio-Board
The audio board is equipped with two radio circuits for four audio channels. Each radio
circuit is assigned to two audio channels using different transmission cycles. For the radio
circuit eight radio channels are available (channel zero to channel seven). Via two
address jumpers on the audio board every radio circuit is assigned to a certain radio
channel. Using two or even more audio boards, these channels must be set up in thew
way that every radio circuit is transmitting a a separate channel. Setting the jumper to
channel “eight” switches the circuit off.
(See also figure: Audio-Board, Jumpers on page .. and figure Modul-Wiring on page ..)
The audio data are transmitted in individual packets in the given transmission cycles. The
package size to the data is constant. The received audio data is decoded on the audio
board into a steady digital audio signal and afterwards decoded into an analog audio
system. After proper amplification the audio signal is fed to the certain audio output
connector on the audio board. The maximum output level of the electronically ballanced
outputs is +10dBu.
Each of the two radio circuits is connected to the antenna splitter board via one send and
one receive antenna patch cable. Thus a total of four SMA patch cables are connected to
the audio board.
The available four audio outputs channels can be used in two different ways. Via jumpers
on the board the outputs are configured. For every channel can be choosen whether it
carries the individual channel’s audio signal or the mix of all four channels of this audio
board. For a separate sound reinforcement system it is recommended to use the
individual channels of all four outputs and mix these signals with an automatic mixer (IRP
Voice-Matic) to increase the gain before feedback. Thus a significant higher
reinforcement level is achievable.
