DMX Stops when Software is Closed

I am trying to install a Doug Fleenor Pre-10A in an auditorium. www.dfd.com/p10a.html

The Pre-10A takes a snapshot of DMX values coming in and stores them in 10 Pre-Sets. I would like to use this so I can shut down my Hog 3 PC software and still be able to turn on house lights for cleaning/maintenance in the room. The Pre-10A only activates when DMX is not present. The Widget however seems to be outputting DMX even when the software is closed.

Is there a setting to disable this feature?
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