Not My Fault!!!

What happens if you have A on one and B on the other?

Nothing. The train will not start. I tried. 

The console and chassis interact with each other only when they are in the same position (both in position "A" or both in position "B"). But I strongly suggest using the "A", because the train starts and stops gradually, smoothly, it's more realistic. When using "B" it stops at once, abruptly. I wonder why didn't they make them both in the same way. I really don't like the way the train stops when "B" is used.

It seems to me that there are still some unanswered questions. Can one controller control two trains by switching positions on the controller? If not, why are there positions A and B at all? Maybe because two controllers can be used at the same time and each of them controls one train? These positions (A and B) are bands, channels, so the two devices (controller and chassis) must be equally tuned to recognize each other.  What would happen if you try using two controllers to control two trains without setting them in different positions? Probably a mess...

We'll presumably know the answers when someone gets two sets.