No, there's no manual.
Configuration should be simple, make midi from Cubase go to the preenfm2 hardware, make midi out from the preenfm2 go to cubase.
Disable midi thru in preenfm2. Make the preenfm2 sends and receives NRPN.
Becarefull to midi loop.
I don't have Cubase so i cannot give more details.
Xavier