DDA-4320 & ZDA-4320RH Instruction Book
Revision 7
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Page 4 of 16
4320-DDA_ib_Rev7.doc
IRT Eurocard
Type DDA-4320
ASI / SDI / STM-1 Path Protection and Distribution Amplifier
&
ZDA-4320RH
Handshake Changeover Assembly
General Description
The DDA-4320 path protection and distribution amplifier covers a wide range of distribution and monitoring
functions for ASI, SDI or STM-1 signals.
Four outputs are provided at the rear of the module. The rear assembly includes a bypass relay to switch the Input
to Output 6
1
in the event of a power failure.
The DDA-4320 incorporates a protection facility for switching three of the outputs between signals from a
companion DDA-4320 when a loss of input is detected. For this configuration, a special double width rear assembly
(type ZDA-4320RH) is required to link the signal and logic sections of the two modules.
Changeover-inhibit and changeover-request switches are provided on the front panel for use where modules are
so linked.
A manual changeover request may be made either locally by using the front panel switch, remotely via a
connection on the rear assembly, or via Simple Network Management Protocol (SNMP) when installed in an IRT
frame fitted with SNMP capability.
Applications:
•
Stand alone cable equaliser and distribution amplifier.
•
Paired for redundant path protection switching.
Standard features:
•
For use as buffer or distribution amplifier.
•
4 x in-phase reclocked outputs.
•
Protection switching capability.
•
Selectable for either ASI, SDI or STM-1 applications.
•
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 (ASI/SDI) or
155 Mb/s (STM-1).
•
SNMP monitoring and control.
Accessories available:
ZDA-4320RH double rear assembly for handshake:
Connects two adjacent DDA-4320’s for automatic
changeover of five of the six outputs in the event of a fault
being detected, plus pass through of the remaining one on
both cards.
1
NOTE: Four Outputs only - outputs 3 & 4 not fitted.