QTR-Quadtone RIP

Getting message "Could not find PPD file for Quad1400-MIS"  when trying to create curve 
files.  Just started using it this week.  I feel like I'm on the home stretch but can get past this.  
I'm not sure what PPD files are?  I didn't see any of these files when I downloaded the 
program.  If I can get this thing to work I'll gladly pay the $50 fee.  I've read all of the 
documentation that I can find for the program; it's been somewhat of a struggle but I feel I'm 
making a lot of headway.

Thanks in advance for your help!
Randy