Brent Brown wrote :

> > RS-485 is a single signal on a differential pair, and it
> > is only driven in one direction and passively pulled
> > in the other...

> Are you sure about that... ?
> My understanding of RS485 (correct me if I'm wrong) 
> is that when transmitting a '1', one line is actively driven
> high (5V) and the other is actively driven low (0V), and
> the reverse for sending a '0'. Nothing passive about it.

But then, how do you connect the 32 "nodes" on a single
RS485 "network" ? (32 according to the original spec, newer
hardware can handle a higher number of concurrent nodes
due to higher "off" impedance in CMOS then in the original
bipolar devices when the spec was written...)

Jan-Erik.



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