Biamp Vocia VA-8150CV Mode D'emploi page 9

Output Fault Detection
Vocia amplifiers employ multiple out-of-band (inaudible), high frequency tones for fault detection. To
prevent the possibility of interference with these tones, recorded audio messages or audio content with
continuous or swept tonal components (e.g. alert tones) should be band limited at 15 kHz during
recording. In addition, signal levels should be adjusted to minimize clipping as severely clipped signals
may also affect these out-of-band fault detection tones.
Failover Modes
The Vocia Amplifiers support a Device-to Device, Channel-to-Channel and 3-to-1 / 7-to-1* failover mode.
Only one type of failover mode can be implemented per amplifier.
Failover is triggered by one of the following conditions:

Chassis fault on primary amplifier

Channel fault on primary amplifier

Loss of power to the primary amplifier

Loss of CobraNet link to primary amplifier

Loss of Failover Link connection

ELD-1 / PLD-2 speaker line fault if enabled in software
Only faults (Chassis and Channel) trigger the failover mechanism. Abnormal conditions that do not
immediately impair audio appear as warnings, but do not trigger failover.
The redundant amplifier may be wired in parallel to the existing speaker line or it can be connected to a
redundant speaker line. Relays isolate the output terminals on the secondary amplifier unit. Relays are
normally open. When a configuration is received, relays close on the primary unit and remain open on the
redundant unit. On failover, the relay states are reversed.
*7-to-1 failover on VA-8150CV only
Device-to-Device Failover wiring with Parallel Speaker wiring
After replacing the faulty amplifier, a power cycle is required to recover from failover. This can be done
either by physically repowering the amplifiers or by performing a 'device reset' in the Vocia software via
the amplifier test tab. The amplifiers are required to be reset within 10 seconds of each other in order for
the primary device to resume control.
VA-8150CV / VA-4300CV Fault Detection