(me too)! Re: [Soekris] rs485 instead of rs232

[Henry Spencer]

On Thu, 1 Jul 2004, Louis A. Mamakos wrote:
> Some RS-485 networks are built with a single pair of wires...
> The addressing capability usually requires special UART hardware
> that can send 9 bit characters, where the high bit is used to mark
> an address for the following frame.

That convention *is* commonly used, but it's by no means universal.
(I speak as someone who designed a protocol that started out using
this approach, progressed through one or two intermediate steps, and
ended up using straight 8-bit characters because doing the 9-bit trick
was too difficult on some of the hardware.)

                                                          Henry Spencer
                                                       henry at spsystems.net