The RB-FS82 8 + 2 audio backup switcher is an important tool in many critical areas of telecommunications and broadcast chains.

The unit has 8 main + 2 backup stereo analogue audio inputs/outputs, digital AES/EBU audio and RS232 connections (inputs and outputs) and can be configured via Ethernet for two main operational applications:

- For switching program sources to a backup destination in case of destination failure ('Backup to outputs'). Typically, this would be audio encoders at the head of program distribution (for audio over IP, E1 or other carrier networks), with "N" x programs feeding "N" x encoders. If an encoder fails, the audio intended for that encoder is routed to a backup encoder, thus ensuring audio continuity to the network transport.

- Switching program sources, including backup sources, to destinations in case of source failure ('Backup to inputs'). Typically, this would be audio decoders at a transmission site with "N" x programs and "N" x decoders feeding "N" x transmitters. If a decoder fails, audio from a backup decoder, or another audio source such as an mp3 player, replaces the signal path to the transmitter, thus ensuring on-air continuity.

The RB-FS82 supports any configuration up to 8 main program signal paths (N ≤ 8) and there are 2 backup program signal paths, in either mode of operation. Each program path simultaneously switches L/R analogue audio, AES/EBU digital audio and RS232 data. Each of these signals is wired to D-sub connectors on the rear panel.

All signal paths are passive and therefore completely transparent using relay-based switching. This has the advantage of a "straight wire" topology during normal (non-alarm) operation and also during any power failure of the unit. An additional advantage of the passive signal path is AES/EBU bit transparency allowing AC3 Dolby E (TM) AES/EBU signals to pass through.

To ensure the passive nature of the unit, switching is determined by (General Purpose) alarm inputs, this alarm signalling normally being provided by the encoder or decoders (or other devices) on site. Recognising the mission critical nature of the system, a high quality relay is used in the RB-FS82.

The passive design ensures audio continuity in case of power failure. However, the RB-FS82 also includes dual redundant power supplies (AC with DC backup as standard, or dual DC by ordering the RB-FS82DC). This means that if one power supply fails, the other is ready to take over. In the extremely unlikely event that both fail, the unit's passive signal path ensures a direct connection for all 8 program streams (analogue, AES/EBU & RS232). This is essential for applications such as transmitter site installation, where a power failure of the unit will not prevent the input audio signal from being transmitted to each of the 8 supported transmitters.

A row of LEDs on the front panel confirms the unit's status, with each individual program path being indicated as being in alarm with either Backup 1 or Backup 2 clearly confirmed as actively replacing the failed signal. Front panel alarm LEDs are also indicated for Power Supply 1 failure and Power Supply 2 failure and these are also reflected by the unit's own general purpose outputs, thus facilitating easy interfacing of the unit with the addition of a summary alarm status GPO output. If the alarm disappears, the unit will automatically return to normal operation, but a manual reversion mode is also provided, allowing technical investigation without the unit "hunting" between different signal paths. Two front panel buttons, RESTORE 1 and RESTORE 2, allow manual restoration of previously failed signal paths from Backup 1 and Backup 2 respectively, and these can be remotely controlled via Ethernet.

To facilitate integration with site management systems, the RB-FS82 supports SNMP control and is configured through a simple web GUI interface.

Contact Sonifex for more information if you have a particular need that is not covered by the RB-FS82 as standard.


RB-FS82 Key Features

- 1U rack mounting.
- Relay-based switching.
- Dual DC, or AC power supplies (to be selected when ordering).
- Encoder site (Set via IP): 8 stereo program inputs, 8 + 2 stereo program outputs where each program input/output includes: L/R analogue, stereo AES/EBU & RS232.
- Encoder site: Each program output has a GP alarm detection input.
- Decoder site (Set via IP): 8 +2 stereo program inputs, 8 program outputs where each program input includes: L/R analogue, stereo AES/EBU & RS232.
- Decoder site: Each program input has a GP alarm detection input.
- Transparent AES/EBU (for Dolby E transport).
- Passive pass-through on power failure.
- GPO output for RB-FS82 alarm condition signalling: PSU 1/2 Failure, Backup 1/2 Active, Summary Alarm.
- Automatic or manual reversion modes.
- Front panel LED indicators.
- IP control, including Web GUI and SNMP.