NGNN CAO,
The configuration that you are currently using, routing the 6653 through a DAQmx device to generate the Timing Source is actually the only way that one can presently use a non-DAQmx device to control a Timed Loop. Because the DAQmx driver API is used to create this Timing Source non-DAQmx devices cannot be directly used for this.
Regards,
Scott T
Applications Engineer
National Instruments