On May 2, 2009, at 8:49 PM, peter green wrote:

>>  my question is: can ethernet be used as a BUS?
>>
> Old-school coaxial 10BASE5 and 10BASE2 ethernet was a bus network.

Old-school 10base5 and 10base2 also required large and expensive  
"transceiver" units in between the "phy" controller and the "bus"  
cable (complete with internal DC-DC converters to power the  
transceiver electronics while maintaining isolation.)   A single-chip  
10baseT hub/switch is MUCH simpler.  I believe that it's possible to  
use some of these chips without magnetics when you don't need  
isolation, further simplifying things (but with the price of off-the- 
shelf hubs, I'm not sure there's much point.)

BillW

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