Bosch 3922 988 43318 User Manual

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Bosch Security Systems | 04-2003 | 3922 988 43318 en
Digital Congress Network | Installation  and Operating Manual | Chapter 4 - Central Control Equipment
en | 4-15
LBB 3508/00 & LBB 3508/00D Audio Media Interface and Power Supply Unit
4.11   LBB 3508/00  & LBB 3508/00D                               
Audio Media Interface and Power Supply Unit
The Audio Media Interface Unit is remotely controlled by the CCU and enables external analogue 
equipment to be connected to DCN’s digital network - such as broadcast, recording, and sound 
distribution equipment. The unit is equipped with four Digital to Analogue convertors with channel 
select switches for the selection of the floor or interpretation channels. The units built-in power supply 
for up to an additional 90* PCF points. Its built-in trunk-line splitter enables the unit to be connected 
to the trunk-line using the loop-through cabling method.
*The figure stated represents the number of units rated with a Power Consumption Factor (PCF) of 
1. For further information regarding the Power Consumption Factor refer to 
 “System 
design fundamentals”.
The unit connects to the main trunk-line cabling using the loop-through method of cabling and is 
switched on automatically when the main Central Control Unit is switched on. The unit can be free-
standing on a table top or with the use of brackets supplied with the unit (Chapter 4.12) can be 
mounted in to a 19” rack. Mounting the unit is similar to CCU mounting.
Controls and Indicators
 
(see
1. Power On indicator (green LED).
2. 4 x 15-position rotary channel selector controls for Outputs 1, 2, 3 and 4.
3. 5-position output selector to select audio output for monitoring (Output 1 - 4 and off).
4. 6.3 mm stereo jack Headphone connector for audio monitoring.
5. 4 x 3-pin XLR male audio output sockets (balanced).
6. 1 x Trunk-line outlet connector for loop-through connection** (without regeneration) of the 
trunk-line plus indicator (red LED) to indicate trunk-line overload. The outlet is protected against 
short circuit of the d.c. supply lines.
7. 2 x Tap-off outlet trunk-line cable connectors** (with regeneration)***. Each outlet includes an      
indicator (red LED) to indicate trunk-line overload. Each outlet is protected against short-circuit 
of the d.c. supply lines.
8. Euro mains socket (a.c. mains voltage selectable inside the unit) with built-in fuse. Mains cable 1.7 
m (5.5 ft.) (D-version 2.5 m (8.2 ft.) long included.
9. 3 indicators to indicate trunk-line overload (red LEDs).
10. 2 m (6.5 ft.) long cable terminated with a moulded 6-pole circular connector for connection to 
the DCN Network Cable
11. 4 x audio output cinch-type sockets (Asymmetrical)
Mains connection
For mains voltage selection, fuse rating and mains cable and plug and socket connections 
refer to the Central Control Unit LBB 3500/xx. (Chapter 4.4.1). 
 
A mains tally, showing 
the connection details is visible on one side of the unit once the top cover is removed. 
The fuse ratings are the same as used for the CCU LBB 3500/05. 
The unit must be powered via an earthed mains outlet.
**   For connection of contribution, distribution, and interpretation units, plus ext. power supplies.
*** For more information on regeneration see 
.
FIG 4-11 LBB 3508/00 Audio Media Interface Unit (Front and rear view)
XLR Connector
(Male)
Earth (1)
(2) Signal -
(3) 
Signal +
Cinch Connector
(Male)
Signal +
Screen
1
2
3
4
5
6
7
8
11
10
9