Digital BW, The Print

Can anyone point me to sources providing an explanation of the ABW
option on the 2400.  I have Clayton's very useful article and have
searched the archives, but I am still unsure of how to proceed other
than on a hit or miss basis.  I understand that the color wheel
adjustments control the color inks used to tone the print, but I would
like a some understanding of what is going on beyond that before I
experiment.  

Thanks,

Steve