QTR-Quadtone RIP

After fooling around with my (R2400) CIS system and getting back to printing under QTR, I ran into a roadblock.  When attempting to print I get the message ""Printer Off line."  This is clearly not the case because I can print using the Epson driver.

I've changed USB cables, choice of sockets, restarting printer, restarting the iMac, and finally, I reinstalled the QTR application - all to no avail.  The same message appears.