System Description; Functionality - AVT Magic Touch Operating Manual

2 S Y S T E M D E S C R I P T I O N
The block diagram of the system is shown in Fig. 2.
FIG. 2
RS 232C
TTL USER I/O
HSD (Relay)
LSD (Keypad)
AES/EBU
Analogue
2.1

Functionality

The Telephone Hybrid system has a maximum of four MAGIC ISDN Tele-
phone Hybrids, which are connected via the Extension Bus. Therefore a maxi-
mum of 8 S
0
are available to the user. Additionally, a Handset or MAGIC Hybrid Headset can
be connected to the front side of the system.
With the optional AES/EBU/ANALOGUE Module, any part of the system can
be extended by two Audio inputs/outputs.
Via the Telephone Hybrid system - depending on the build - up to 16 callers
can be put On Air or in Pre Talk simultaneously. Additionally, there are con-
figurable call forwarding possibilities.
For each caller, a digital Echo Canceller is available. This echo canceller is nec-
essary to suppress disturbing echos when the caller is using a normal ana-
logue telephone.
Likewise, the Automatic Gain Control (AGC) can be switched on for each
caller.
To suppress disturbing noise from callers who are currently not speaking, the
Expander can be activated.
In the conference mode there is the possibility of mixing all callers digitally
THE BLOCK DIAGRAM OF THE MAGIC ISDN TELEPHONE HYBRID
basic construction
AES/EBU
Channel 1
ANALOGUE
Channel 2
Module
Channel 1
Channel 2
(Option)
Audio codec
- Analogue Audio
- G.711 Codec
interfaces as well as 4 analogue Audio inputs and Audio outputs
S y s t e m D e s c r i p t i o n
interfaces
2 x S
ISDN Module
DSP
- Echo Canceller
- N-1, AGC
Standard
- Digital Mixing
Audio
interface
Handset
Audio (CMD)
Extension Bus
Line
0
P A G E 1 9