Spektrum receivers - Channel inputs?

[Chief58D]

Just reviewing the latest Spektrum receiver comparison chart from their website, and noticed that several of their receivers have “many” more input channels than output channels (AR637T has 6 output channels, but lists 20 input channels!) I’m assuming these input channels are used for SMART/AS3X switching, throttle reverse, etc.

Is my assumption correct, and is there a reference that specifies what types of functions use one or more receiver input channels to perform the required task?
Thanks!

[xviper]

I call them "ghost" channels. You can't actually plug any more than the available 6 ports but more, higher channels can work for "smart" stuff via some sort of feedback pathway. Eg, thrust reverse works via Ch. 7 (or whatever channel you choose) as a feedback through the throttle signal wire. I don't fully inderstand the mechanism of how it really works.

[Chief58D]

LOL- same here, “ghost” channels sound like a good explanation to me. Thanks!
I’m still far from mastering all the Spektrum Gen2 & later radio capabilities .

Radios we’re SO much easier when all we had was dual rates on the front, and DIP switches for servo reversing hidden behind the back panel…
But I do appreciate modern radio capabilities, even if I haven’t quite figured out all the features yet…