DDA-4320:   ASI / SDI / STM-1 Path Protection & Distribution Amplifier.

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 250m.
      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.

Brochure  

User Manual  

GENERAL:


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 61 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.


NOTE: 1     4 Outputs only - Outputs 3 & 4 not fitted.


TECHNICAL SPECIFICATIONS:


Input:
Number
1.
Impedance
75 Ω, BNC.
Type
270Mb/s ASI / SDI;
or 155Mb/s STM-1.
Return loss
15dB 5 MHz to 270 MHz.
Equalisation
Automatic, better than 250 metres at 270 Mb/s for Belden 8281 or equivalent cable (reduces to approx. 200m when SW3-4 is ON).

Outputs:
Number
4 ASI / SDI, or STM-1.
(Relay bypass of input (SK2) to output (SK3) on loss of power or removal of card).
Type
Reclocked.
Level
800 mV ħ 10% (270Mb/s ASI / SDI / STM-1 NRZ encoded);
1.0 V. ħ 10% into 75 Ω (STM-1 CMI encoded).
Impedance
75 Ω, BNC.
Return loss
15dB 5 MHz to 270 MHz.
DC offset
Nil.

Performance:
Reclocking
Selectable for 270 Mb/s ASI / SDI, or 155 Mb/s STM-1 operation.
Rise time
< 1.5 ns, (850 ps typically).
Intrinsic jitter
< 0.1 UI (measured with up to 300m of Belden 8281 or equivalent cable).

Alarm:
Connector type
3-pin Phoenix style.
                       Signal loss
Open circuit on loss of input or input signal does not match set rate (not locked), or AIS detected in STM-1 data.
                       Power loss
Open circuit on loss of power.

Power Requirements:
Voltage
28 Vac CT (14-0-14) or ±16 Vdc.
Power consumption
6.5 VA.

Other:
Temperature range
0 - 50°C ambient.
Mechanical
Suitable for mounting in IRT 19" rack chassis with input, output and power connections on the rear panel.
Finish:             Front panel
Grey background, black lettering & red IRT logo.
                       Rear Panel
Detachable silk-screened PCB with direct mount connectors to Eurocard and external signals.
Dimensions
6 HP x 3 U x 220 mm IRT Eurocard.
Standard
Rear connector assembly with matching connector for alarm output.
Optional
SMU-4000 SNMP plug-in module for use with 4000 series frame fitted with SNMP "Agent".
ZDA-4320RH double width rear assembly, for handshake connection of two DDA-4320's.



           



Due to our policy of continuing development, these specifications are subject to change without notice.