Hello Fluxengr. Thank you for contacting National Instruments. You can specify the state on which the program is clocking in the active edge input of DAQmx Timing.vi. If you are using Traditional DAQ with pattern I/O, the REQ polarity is active low, which means data is either latched or output on the falling edge of the clock. (http://digital.ni.com/public.nsf/websearch/2FB93421FAD8374286256BDF007A78AF?OpenDocument) Please let me know if you have any questions. Have a great day!
Marni S.
National Instruments