Also can I run PS1 & PS2 locomotives with the WiFi system?
You run the PS2 engine using the Premium DCS App's Engine Control Screen and the PS1 engine using the Track Control Screen.
How do I determine the current software level in my TIU?
From the DCS App's More... Screen, navigate to Advanced Features, System Settings, TIU Settings, select your TIU and tap on TIU firmware near the top of the screen.
This and a whole lot more about DCS WiFi is all in MTH’s “The DCS WiFi Companion 2nd Edition!"