Turns out the CDSO32 part (representing the Contec BO-32L-PE binary output) rquires two inputs. One for the first 16 bits, and one for the second set of 16 bits. So Alex added another input to the part in the library. Its still a bit strange, as it seems the In1 represents the second set of 16 bits, and the In2 represents the first set of 16 bits.
I added two sliders on the CustomAdls/C1TST_ETMY.adl control screen (upper left), along with a bit readout display, which shows the bitwise and of the two slider channels. For the moment, I still can't see any output voltage on any of the DO pins, no matter what output I set.