This was talked about by Victron at Intersolar this year. In an offgrid system, you can connect a generator to the output of a Multi/Quattro.
The way it seems to work is that the Generator is also wired to the input, once the Multi has synced with the Generator the relay on the closes a NO contactor connection the Generator to the Multi output.
Is there any Victron documentation on the correct implementation of this? The programmable relay assistant can be programmed to switch on when AC is available on AC1, but it doesn't explicitly state that this will only happen once the Multi has synced with this AC source. 
