MC2 Audio ti series Instruction Manual page 43

If required, the front panel pots can be disabled – this setting can be monitored
through ICORE, but not adjusted. Please see the section on page 49 for how to
disable these controls.
*Muting is specified as –90dB gain reduction relative to 0dB and this is only
possible using the mute facility – the amount of gain reduction possible using the
digital VCA control is –60dB.
Master and backup amplifier configuration with automatic switchover
In safety critical applications, it may sometimes be necessary to ensure that the
audio signal is not interrupted by the possibility of amplifier failure. The most
important amplifier channels may be "backed up" using a slave amplifier,
normally held in standby. This will automatically take over from the main
amplifier if there is a power failure to the main device, or it goes into "Protect" for
any reason.
This scenario can be easily achieved with a simple connection between the two
amplifiers and a few configuration changes through ICORE.
It is clearer to explain how this will work by considering the physical configuration
first of all, then the settings required through ICORE.
To monitor the state of the master amplifier effectively, we must not only watch
the GPO line for the protect signal, but also know when the amplifier has lost
power for any reason. This is achieved by not directly using the GPO line for the
protect signal, but using the 3v3 line through the relay's normally closed
connection.
Amplifier Operator's Manual Page 43