The DDA-4320 path protection and distribution amplifiers, From IRT Electronics cover a wide range of distribution and monitoring functions for ASI, SDI or STM-1 signals.
Six outputs are provided at the rear of the module and one on the front panel for monitoring purposes. The rear assembly includes a bypass relay to switch the Input to Output 6 in the event of a power failure.
The DDA-4320 path protection and distribution amplifiers incorporate a protection facility for switching five 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.
Features of the DDA-4320 path protection and distribution amplifier:
- Optional plug-in SNMP monitoring and control module
- For use as buffer or distribution amplifier
- Six in-phase re-clocked outputs
- Protection switching capability
- Selectable for either ASI / SDI or STM-1 applications
- 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)
- Automatic input equalisation to 250 m
- Automatic output muting on no input