Hi Jarvis,
Unfortunately, wired-or can only be used in an unstrobed operation (no pattern I/O).  This means it can only be configured by the DIG_Prt_Config and not DIG_Block_Config.  The following knowledge base and its links are helpful in understanding how it works with the 6534.  Hope that helps clear things up. 
What Is Tri-State and Which DAQ Devices Support It?
http://digital.ni.com/public.nsf/websearch/09B559BE292C75DB8625698500640E0A?OpenDocument
Ron