System information

FCD 901 48
Issue R2A, 07.2009
XMP1 Release 5.5 System Description
Conference Circuits
Page 2-42 Proprietary Information Aastra
2.6 Conference Circuits
2.6.1 Digital conference for data channels
The channel modules permit a “digital conference” to be switched. In such
a digital conference, several sub-stations (DTE) can be connected to one
main station.
This main station can then exchange data with the sub-stations (DTE). The
identification of the desired DTE takes place via the protocols exchanged
between the main station and the DTE.
In the receive direction, each sub-station (DTE) receives the signal sent by
the main station. In the transmit direction, the signals from the sub-stations
are linked via an AND gate in the digital conference circuit and are then
transmitted to the main station.
In the quiescent state, the signal is logic "1".
Each logic "0" is transmitted to the main station.
On one module, a maximum of 7 converter signals can be involved in a
digital conference. This number is reduced by the number of interfaces
connected.
Converters not participating in the digital conference can be used for other
applications.
When a digital conference is switched, converter 1 is not available for other
applications.
The alarms of converters n and converter 1 involved in the digital
conference must be suppressed.
Figure 2.23: Block diagram of a digital conference
Main station
Sub-station 1
DTE DTEDTE
Sub-station n
Sub-station 2
Port
DSK
Port Port Port
Port
2 Mbit/s 2 Mbit/s
DSK
DSK
Node 1
Node 2
Node 3