Forums

RS485, multidrop protocol

Started by Ian McCrum MI5AFL November 14, 2004
Wow, a long thread, Thanks for the inputs, I am following up on the
links.

It looks like there is no clear cut winner in getting, say half a
dozen machines linked using RS485, a simple master-slave polling
scheme, where machines queue up outgoing requests and only speak when
spoken to would be simplest. The other candidates seem onerous.

The real trick will be to provide a physical layer that can link to a
standard TCP protocol stack.

When I get my linux board I'll start dismantling some of the ethernet
drivers, maybe I can "fool" the TCP/IP stack to think it is connected
to a perfect (unbusy) network.

I'll revisit slip and ppp then.

Thanks again
Ian McCrum MI5AFL.
( actually I just realised AX25 might be a good candidate as well...)
University of Ulster



Ian McCrum MI5AFL wrote:
> Wow, a long thread, Thanks for the inputs, I am following up on the > links. > > It looks like there is no clear cut winner in getting, say half a > dozen machines linked using RS485, a simple master-slave polling > scheme, where machines queue up outgoing requests and only speak when > spoken to would be simplest. The other candidates seem onerous. > >> Thanks again > Ian McCrum MI5AFL. > ( actually I just realised AX25 might be a good candidate as well...) > University of Ulster
www.micrium.com offers an inexpensive ModBus package. Scott
Ted Wood schrieb:
> Ian McCrum MI5AFL <IJ.McCrum@ulster.ac.uk> wrote in message news:<67gfp0dr2na07h75ic7i939d15r2pelcf5@4ax.com>... > > try:
---8<---- http://www.p-net.dk cheers Gunther