Sonifex RB-FS42 Audio Failover Switcher, 4 Main I/O, 2 Standby I/O

Sonifex RB-FS42 Audio Failover Switcher, 4 Main I/O, 2 Standby I/O

A reduced channel count variant of the RB-FS82 with fewer inputs and outputs is the RB-FS42 4 + 2 audio failover switcher. It supports all of RB-FS82's functionalities and is a more affordable option when failover is required for fewer sources and destinations.

The device can be set via Ethernet for two primary operational purposes. It features four main + two standby, stereo analog audio, AES/EBU digital audio, and RS232 connectors (both inputs and outputs). For "Standbys to outputs," the process of moving program inputs to a backup destination in case the primary destination fails. For audio via IP, E1, or other bearer networks, this would typically involve audio encoders at a program distribution head end, with "N" x programs feeding "N" x encoders. In the event of an encoder failure, the audio intended for that encoder is diverted to a backup encoder, guaranteeing the uninterrupted flow of audio via the network. 

In case of a source failure, switching program sources—including standby sources—to destinations (also known as "standbys to inputs"). This would usually need audio decoders at a transmission site that are fed by "N" x transmitters and "N" x programs. The audio from a backup decoder or another audio source, like an MP3 player, overrides the signal flow to the transmitter in the event of a decoder failure, guaranteeing broadcast continuity. When operating in either mode, the RB-FS42 allows for the design of up to 4 main program signal paths (N < 4), in addition to 2 standby program signal paths. AES/EBU digital audio, RS232 data, and analog L/R audio are all switched simultaneously by each program path. These signals are all connected to D-type connectors on the back.

All signal paths are passive and therefore completely transparent utilising relay based switching. This has the benefit of a “straight wire” topology during normal (alarm free) operation and also during any power outage to the device. An additional benefit of the passive signal path is AES/EBU bit transparency allowing throughput of AES/EBU AC3 Dolby E TM signals.

To ensure the passive nature of the device, switching is determined by alarm (General Purpose) inputs, with this alarm signalling in turn being normally provided by the encoder or decoders (or other devices) at site. Recognising the mission critical nature of the system, a high grade of relay is used in the RB-FS42.
The passive design ensures continuity of audio in the event of any power outage. However the RB-FS42 also includes dual redundant power supplies (85V-264V AC with a 12V 1A DC backup as standard). The RB-FS42-DC model accepts two DC power inputs (24 - 48V DC) via locking 2.5mm pin power connectors and both power supplies are monitored by the unit. This means that if either 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 straight wire connection for all 4 program feeds (analogue, AES/EBU & RS232). This is essential for applications such as installation at transmitter sites, where a power failure to the unit will not prevent the audio input signal from being output to each of the supported 4 transmitters.

A row of LEDs on the front panel confirm the unit status, with each individual program path indicated as being in alarm with either Standby 1 or Standby 2 programs clearly confirmed as actively over-riding the failed signal. Alarm LEDs on the front panel are also indicated for power supply 1 failure and power supply 2 failure and these are mirrored by the device’s own General Purpose Outputs facilitating easy interfacing of the device with the addition of a summary alarm status GPO.

Each signal path's GPI Alarm pin can be monitored and used by the unit to switch between Through, Standby 1, Standby 2, or Silence. When a Main path alert is received, the device will always try to route a Standby path. If both Standby paths are already in use, one of the two remaining alternatives (Through, Silence) will be used. The device can be set up to wait for the pressing of a manual button or to automatically reestablish the main "through" path.

In the event of alarm clearing, the unit will automatically revert to normal operation, but a manual reversion mode is also provided, allowing for engineering investigation without the unit ‘hunting’ between different signal paths. Two buttons on the front panel, RESTORE 1 and RESTORE 2, allow manual restoration of the previously failed signal paths, away from Standby 1 and Standby 2 respectively.

The RB-FS42 is configured using a straightforward web-based GUI and supports SNMP V1 to ease interaction with site management systems. Through SNMP GET requests to the device, all pertinent data about input/output status, alerts, and power supply is accessible. The majority of potential events, such as input GPI alerts and power supply failures, can also result in the generation of traps. If your specific need isn't met by the RB-FS42 as standard, get in touch with Sonifex for more details.

Key Features

• Dual DC, or AC, power supplies (select when ordering).
• Encoder site (Set via IP): 4 stereo program inputs, 4 + 2 stereo program outputs where each program input/ Output carries: analogue L/R, stereo AES/EBU & RS232.
• Encoder site: Each program output has an alarm detect GP input.
• Decoder Site (Set via IP): 4 +2 stereo program inputs, 4 program outputs where each program input carries: analog L/R, stereo AES/EBU & RS232.
• Decoder Site: Each program input has an alarm to detect GP input.
• AES/EBU transparent (for Dolby E transport).
• Passive throughput in the event of a power outage.
• GPO output for signaling RB-FS42 alarm conditions: PSU 1/2 fail, Standby 1/2 active, Summary Alarm.
• Automatic or Manual reversion modes.
• LED indicators on the front panel.
• IP control, including Web GUI and SNMP.