Digital BW, The Print

I'm trying to create printer profile for black and white printing with ABW driver using ProfileMaker.

I can't figure out how to make a grayscale target.
I've used before 51-step target from QuadToneRip, but I get error message "Invalid data type" when I try to make a profile from it with ProfileMaker.

Also I think that 51 step chart is not good enough for quality profile. Please correct me if I'm wrong, I'm no expert by long shot.

ProfileMaker has MeasureTool which contains Test Chart Generator.
But when I try to make RGB (there is no choice for monochrome chart - only RGB and CMYK) chart it gives me 3 RGB channels and I can create only color charts.
Any idea how to make Grayscale chart and how many levels would you recommend?

Thanks so lot for your help,
Jacob Mann
photo3dart.com