VA-8600 Fault Detection
Amplifier-to-Amplifier Failover
Vocia supports one-to-one automatic amplifier failover in case of fault. Failover is triggered by one of the
following conditions:
Chassis fault
Channel fault
Loss of power
Loss of CobraNet link
Loss of Logic I/O
Only faults (e.g., heat sink fault and channel failure fault) trigger the failover mechanism. Warnings
indicate abnormal system conditions that do not immediately impair audio and do not trigger the failover
mechanism.
The redundant amplifier must have the same configuration as the primary amplifier (i.e., amplifier module
count, watts per module, load configuration). A wire failover link cable must be connected between the
primary and the redundant amplifier as shown below. Connect ground to ground and logic 4 of the
primary amplifier to logic 3 of the redundant amplifier; connect logic 3 of the primary amplifier to logic 4 of
the redundant amplifier. Leave logic 1 and 2 disconnected. The redundant amplifier can be wired in
parallel to the existing speaker line or it can be connected to a redundant speaker line (see figure below).
Relays isolate the output terminals on the secondary VA-8600 or VA-8600c unit. Relays are normally
open. When a configuration is received, relays close on the primary VA-8600 or VA-8600c and remain
open on the redundant VA-8600 or VA-8600c. On failover, the relay position is switched.
After replacing the faulty amplifier, a power cycle is required to recover from failover. The primary device
will resume control after the fail condition is cleared and the unit is re-powered.
