4007-dda.ib.rev1.doc
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15/09/2008
DDA-4007
270 Mb/s ASI/SDI 8 O/P
Reclocking Distribution Amplifier
General Description
The DDA-4007 270 Mb/s serial digital video distribution amplifier provides the user with a single standard module
to cover a wide range of distribution and monitoring functions for SDI or ASI signals.
Due to the fact that standard loop through techniques used in the analogue domain are unsuitable to the digital
domain most digital equipment comes with no facility to route the input signal to other locations. As a result a VDA
is required at almost every point in the digital chain.
Serial digital signals also suffer severe deterioration over relatively short cable distances. The DDA-4007 provides a
means of extending the working distances that can be achieved by equalising, reclocking and re-transmitting the
data mid route.
Where a large number of reclocked outputs are required the DDA-4007 may be used to provide reclocking and its
outputs fed to one or more non reclocking DA’s to provide the number of outputs required. This provides a more
economic solution than using multiple reclocking DA’s and minimises jitter increase due to unnecessary
re-clocking.
The rear assembly now includes a bypass relay, to switch the Input (SK1) to Output 1 (SK2) in the event of a power
failure, as standard.
An optional Simple Network Management Protocol (SNMP) plug-in module is available for remote monitoring of
input status and alarm state.
The DDA-4007 is designed to fit IRT’s standard Eurocard frames as well as IRT’s 4000 series frame for use with
IRT’s SNMP system and may be used alongside any other of IRT’s analogue or digital Eurocards.
Features:
•
For use as buffer or distribution amplifier.
•
8 x in-phase 270 Mb/s ASI or SDI reclocked outputs.
•
Automatic input equalisation to 250 metres.
•
Automatic output muting on no input.
•
Relay bypass on loss of power.
•
Front panel indicators provide monitoring of presence of input signal at 270 Mb/s.
•
Optional plug-in SNMP monitoring module.
O/P 2
O/P 3
O/P 4
O/P 5
O/P 6
O/P 7
O/P 8
OUTPUTS
EQUALISER
RECLOCKING
SIGNAL FAIL
DETECTION
INPUT
Relay RL 1 = Output Alarm
LINK
ALARM O/P
RL 1
BLOCK DIAGRAM DDA-4007 SIGNAL PATH
O/P 1
MON O/P
Relay Bypass on loss of power
RL1
SNMP