You are correct, no pulse, no frequency, no data able to cross any reference lines and thus read by a histogram. As I cannot find a sub VI that will read extreme Duty cycle values without saying there is an error or that D.C. is 50%, I have come to a solution: get rid of the darn VIs that use these means of measurement. Instead I used the "Amplitude and Level Measurements" VI and looked at the RMS output. I knew from my input, +12V should be 100%, and 0V should be 0%. After creation of a table that correlates these variables (equation via MatLab), I then had a valid means of seeing RMS, converting, and reading Duty cycle. I was then able to manipulate my data later in the application. Success!
Thanks for the input,
It is good that you found a solution.
Even though your signal is digital in nature, an analog measurement does the job in this case.
Sometimes looking at a problem from a different perspective helps. That is one of the big values of this Forum: the participants come from many different backgrounds.