I can't tell what the protocol specifies after reading this article. The language seems vague. Perhaps this is due to my ignorance, but I don't think that matters. The article is too difficult to understand as is. For example, from RS-232, we see, "The standard defines the electrical characteristics and timing of signals, the meaning of signals, and the physical size and pin out of connectors." If something like this could be on this page, that would be excellent. Even better would be an overview of the contents of the standard (answering questions like, "What are the electrical characteristics?" and "What are the meaning of signals?", etc.), but that of course would take someone a good deal of time.