Mary,
Thank you so much for the quick response. I double checked myself per your suggestion and it turns out you were right. Originally, I had first signed out of Moodle on my PC and then entered the direct url of the pdf and it opened as I said, however when I went to separate PC that had not been used to log on to Moodle at any previous time, entering the link brought up a Moodle sign in page as you indicated it should. So the error was on my end on that one (the browser must have been retaining some cookie information or something that mistakenly recognized me as still signed into Moodle). My problem has progressed to video playback compatibility, but that is topic of another forum. Thanks again!