Operation Manual

42 Appendix E: XL8 Live Performance System
DL431 Mic Splitter
Operator Manual
All system connections are duplicated for full dual redundancy.
Resilience to failure (redundancy)
The XL8 Live Performance System is tolerant of any single failure of hardware or
software. To achieve this the system employs dual-redundancy, where a key
component has an identical redundant spare that is ready to take over should it fail.
Other failure scenarios are managed by the N+1 principle, where redundant
components form an acceptable fraction of the system; for example, one of the DSP
units in the rack is a redundant spare (see Figure 4 on page 43).
The control surface can tolerate multiple hardware failures without the operator losing
control of the audio. Any of the five GUI screens can be used to operate the whole
control centre, even if no control surface hardware is working.
The system includes diagnostic tools that give advance warning of any poor connectivity
(high error rates), internal temperatures and voltages etc. The system instantly alerts
the operator in the event of any hardware, software or connection failures, and
indicates the location of the fault. The system asks the operator what action to take,
but doesn’t automatically reconfigure. This is so that if, for example, the band is near
the end of a song and the audio is still alright, the mix engineer carry out corrective
action at a more opportune time.
Figure 5 on page 44 shows that even when all of one half of the system is down (the
greyed out portion) it will still function as normal. Although, in practise, it is highly
unlikely that this will ever happen.
Figure 6 on page 45 illustrates what happens when a router fails. Once again, the
system functions perfectly normally.