QTR-Quadtone RIP

I'm brand new to this software.  Have never been able to get anywhere
near darkroom quality on my printer because the coloured inks are
mixed in with the black.  RIP looks (I hope) like the solution.
I've downloaded and installed the RIP software and it's recognised my
RX640, and it shows lots of Printing Models for the 640 and most of
them have curves.

But when I press print having selected the model and a curve the
printer just pushes out blank sheets of paper and eventually prints a
few numbers on each sheet.  Suggests I'm not set up right.

Anybody got any ideas please.  Should I be picking a particular
printing model and a particular curve.

Also would ou recommend any particular JPEG to TIFF conversion
software.  I've got lots of 35mm B&W negs scanned to JPEG that need
converting.

Many thanks.

Peter.