it will give both a audio and a video source availeble on Masterlink.
Meaning you can from a Beovision with masterlink press any audiosource button and the 1611 Beolink converter will activate the correct input pins (1, 4 and 2 for audio) in its datalink connector.
I think that would be the case depending on your setup and goal. My knowledge of the ML/NL converter is limited, so my answer is for the ML part.
in the linked thread it was tested with both Beolab 2000 and 3500 as well as different Beovisions and a Beport without other components in the Masterlink chain.