Technical data

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System Description
2 SYSTEM DESCRIPTION
The functional elements of the system are pictured in Fig. 2.
FIG. 2 FUNCTIONAL ELEMENTS OF THE MAGIC TH2 TELEPHONE HYBRID
2.1 Functionality
The MAGIC TH2 system incorporates an analogue POTS interface as well as
an ISDN interface. The operating mode can be set with the help of a software.
If the ISDN telephone interface is used, two independent telephone hybrids
are available within one system (channel 1 and channel 2). If the analogue
POTS telephone interface is selected, only one line can be used.
The complete signal processing is taken over by a digital signal processor. In
this way the following functions are carried out:
– G.711 Audio encoding and decoding
–two independent Echo Cancellers for each line
–two independent AGCs (Automatic Gain Control)
–two independent Expanders (to suppress spurious signals)
– control of the complete system (Keypad, Display, Relay, TTL, RS232)
As ON AIR Audio interfaces (input/output) for the mixing unit two inde-
pendent analogue channels as well as a optional digital AES/EBU interface
are available. If the AES/EBU interface is selected (optional AES/EBU soft-
ware licence is necessary), both channels are multiplexed together (right/left
channel). The input as well as the output possesses a separate digital Sample
Rate Converter (SRC). For connection with an external clock a clock input and
a clock output are available.