4280-dda.ib.rev0.doc
Page 3 of 17
11/03/2009
IRT Eurocard
Type DDA-4280
2.048 Mbps (E1) G.703
Data Distribution Amplifier
General Description
The DDA-4280 data distribution amplifier is intended for use with E1 data signals conforming to the
ITU Rec. G.703. The DDA-4280 is primarily intended for use in pairs with a double width rear assembly for
automatic path protection applications, although it is supplied as standard with its own rear assembly for stand-alone
applications.
Four outputs are provided at the rear of the module with an additional output for monitoring purposes on the front
panel. One output (O/P 1) is controlled by relays to provide a bypass signal from the input in the event of a power
failure.
Indicators are provided on the front panel for:
Data loss
AIS detect
Module in service
Module in standby
Changeover inhibit and changeover request switches are provided on the front panel for use where modules are
linked in pairs for redundancy. For this configuration the double width rear assembly is needed to link the logic
sections of two modules.
When used as a distribution amplifier the DDA may be housed in any of IRT’s standard Eurocard frames. When
used in pairs for handshake operation only 3 RU chassis types may be used so that the double width rear assembly
may be used.
The DDA-4280 is also equipped with Simple Network Management Protocol (SNMP) monitoring so that status and
alarms can be remotely monitored and controlled via an Ethernet connection. This function is only available when
the unit is housed in an IRT 4000 series frame fitted with an SNMP agent module.
Standard features:
•
Data regeneration with Jitter Attenuator
•
Front panel monitoring facility.
•
Protection switching facility.
•
External alarms and bypass.
•
Redundant pair operation capability.
•
Simple Network Management Protocol (SNMP) monitoring.
