Exactly! - That's why I have become a proponent of using polled networks. I
used to think ARCNET was a poor network choice because of it's speed, but
by not having collisions, it would out-perform 10mb Ethernet when the
network got busy. We switched from ARCNET to Ethernet on our DEC system,
and during busy times of the day, network speeds were terrible. At least
with ARCNET's polled (token ring) protocol, bandwidth was predictable. If
you look at collision detection network bandwidth charts, they go
exponentially down when you get over 40-50% utilization.

Anyway, for most PIC applications, the amount of network traffic works fine
on a polled system, and like I said before, after a year or more of
fighting with collision detection/avoidance without the proper driver
circuitry (which we didn't have the board real-estate or budget to use), we
switched to a polled network (two channels of RS/485) and life was much better.

Howard


At 02:13 PM 10/2/00, you wrote:
>But if you poll you should not have any collisions at all!
>
>Wouter
>
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