USB master on Photon

What is OTG?

I’m interested in controlling an NCE interface for Cab Bus. What the hell is that? It’s a Digital Command and Control (DCC) system for model railroads.

I see what undertone was going thru to control his vacuum and would like to avoid such a setup if possible.

So I was hoping to hook a Particle Photon directly to this:

And issue commands from an IOS app.