Re: RS485 is bidirectional does it mean it is fullduplex?

"Floyd L. Davidson" <floyd@xxxxxxxxxx> wrote in message
news:87mzppg39l.fld@xxxxxxxxxxxxx
>
> The fact is the 100 Ohm load resistor, being of lower resistance
> than any other load on the cable, is what determines the voltage
> levels. The receivers are high impedance voltage sensing devices.

That's a bit simplistic. The driver signal hits the characteristic Z of the
cable first; *that's* what determines the voltage levels. It then travels
along the cable, and eventually hits the last receiver, and its termination
resistor. Ideally, there is at that instant no change in impedance, and
hence no energy to dissipate/find some other how.

In terms of what the receiver sees, however, I agree. But it's not what
(common-mode) we've been arguing about ;).

(BTW, it's now 3:38am here in southern UK, and probably a bit warmer than
where you are ;). Nice pics on your site.)

Steve
http://www.fivetrees.com


.

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