Trigger cable lowers temperatures & power consumption

[kjj11]

I see two inputs for jacks on each Devialets:

RS-232 Control / Optical
Trigger In

What In I may use to connect trigger cable? Trigger In?
And what about Configurator? I need to activated Trigger In on Master only? On Companion Trigger In is not available if I activated Share Inputs on Companion - and on Companion Trigger In is not available if I deactivated Share Inputs on Companion too. Its alvays grey and I cannot activated it

And if I need to choose RS-232 Control I see many option in Configurator - whats need to be activated?

Command acknowledge
Auto change notification
Echo chaining

And what speed I need to set?

Thanks!