On 11/6/2015 10:35 AM, wrote:
...I am trying to learn how these systems are
designed.

The questions you're asking, and the information you want, are/is best
answered/obtained through direct contact with the manufacturers of the
equipment (as opposed to, say, technical sales representatives *representing*
those companies - who themselves [in my engineering experience] are variously
informed from "well" to "not so well.") In the halcyon days of yore, this
often meant digging through a Thomas Register or similar; today the WWW will
likely suffice. But in any case it will likely involve several phone calls and
being routed around inside the home office until you find/are-punted-to
someone on the design side of the product, after (most likely) the people
answering the phones first direct you to (maybe even technical!) sales.

HTH.

Bob W.