Hey Don,
Thank you for contacting National Instruments.
There is not a register-level programming manual for the SCXI-1102. This was a mistake made in the first version January 1996 of the SCXI-1102 manual. This was corrected in the later August of 1997 version.
http://www.ni.com/pdf/manuals/320975b.pdf
Register-level programming is not formally supported by National Instruments. If you would like more information about alternative methods of programming other than NI-DAQ please contact your sales representative.
Best Regards,
Joshua P.
Application Engineering
National Instruments