Hi Joegill,
Follow the link below for a PDF document for a diagram (page 10) on configuring a quarter bridge on a SCXI-1121 module with a SCXI-1321 terminal block. You will notice that R1 & R2 are completion resistors for the configuration. All manuals are online and are generally a great resource for these questions.
http://www.ni.com/pdf/manuals/321924c.pdf
Please let me know if you have any other questions.
Have a great day!
Brooks W.
National Instruments