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3.4. Installation and set up
3.4.1. Mounting and connections
Natural convection or forced air (optional fan) cools the equipment. Avoid obstructing the openings on
the flanges and the rear panel.
To operate the codec, the minimum necessary connections to set up are (see details in the rear panel
description):
•
Power supply ;
•
Audio inputs and outputs (XLR sockets) ;
•
Network interface: S0 interface(s) and/or X24/V11/V35 interface(s) ;
Whenever needed, the Alarm socket (alarm relay contacts) must be connected to an external supervision
system.
The pin out of the connectors is indicated in chapter 5.1: Characteristics of interfaces.
3.4.2. Initial set up
Before the first link, the equipment must be configured according to the desired operation mode (audio
input/output format, coding type and parameters, etc.) and the local conditions (ISDN numbers, network
protocol…).
For using the keyboard, a password may have to be entered. After factory setting or after total
configuration erasure, the password is blank (no password needed). Afterwards, a password can be
programmed by the user if one is needed.
For more details about the codec configuration, see chapter 3.3 (Equipment configuration parameters,
p. 17) and chapter 4 (Detailed operating mode). The setup of the optional Ethernet interface is described
in chapter 6.1 (Ethernet Remote Control option).
3.4.3. Notes about the use of AES/EBU interfaces
When using digital audio interfaces, it must be decided whether the codec is “master” or “slave”
regarding audio sampling clock synchronisation. In the first case, the codec derives the sampling clock
from the network clock, and the device(s) connected to the codec must synchronise to the same clock
source.
The most common choice is rather the “slave” mode, to be used when it is not possible (or not desired) to
synchronise the external equipment onto the clock of the transmission link. In this case, the AES/EBU
interfaces should be set in the so-called “asynchronous” mode (wherein the AES interfaces are not
synchronous with the network clock). When in this mode, the codec derives the sampling clock of the
digital audio interfaces from its AES input, and sampling rate conversion (SRC) is used for interfacing to
the coding parts.
It is mandatory in such situation to provide the codec input with an AES signal featuring the same
sampling frequency as the external equipment, even if the codec is used only as a decoder. If this
requirement is ignored, the unit will exhibit unpredictable behaviour as it is left with a floating or wrong
reference clock.
If, on the contrary, it is decided to synchronise the external equipment (at 48 kHz or 32 kHz) onto the
transmission clock, the codec must be configured in “synchronous” mode. In this case, the output is
locked onto this clock, and it can be used as a reference to synchronise the equipment connected to the
codec output; the “Sync” socket also outputs separate signals for this purpose (see description in 3.2.2,
p. 16 and pinout in 5.1.10, p. 62). The digital audio signal at the codec input must then come from a
device synchronised by this way.
55 000 039 - Ed. F
HIFISCOOP 3 5ASystem - User manual
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January 2006
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Hifiscoop 3 5AS Manual - Ed.F.doc