I just had to stick in my 2.1 cents worth (inflation, you know...) on this
issue. I will *never again* use 10base2 for plant wiring for the simple
reason that 10base2 (and 10base5) provide a ready path for "ground loops"
between all the equipment sharing the cable. It's true that the "grounds"
are "supposed" to be isolated (to the tune of several Kvolts) from the
computer connection, but, believe me: "sh*t happens." And the results
can be dangerous.
10baseT is designed to be isolated at every connection point in the "star"
configuration (high-isolation transformer coupling,) so there is a much less
likely path for the "big ugly voltage" from one piece of defective equipment
that just happens to be shorted to the Ethernet 10base2 cable. You don't
get killed when you reach behind your computer and grab the Ethernet cable
and suddenly find it has 480vac on it due to some stupid short in a control
cabinet. If the 10baseT cable is shorted, the hub has a high potential, but
it never makes it out to any of the other cables plugged into the hub.
Both of these scenarios assume correctly isolated cable-to-interface
connections. It's just there is nothing isolating the bad stuff from
you when you touch the cable shield. The necessary hub on 10baseT
keeps the bad stuff from getting past the first short - assuming you
*do* use a hub...
And making 10baseT connections (with the proper 50US$ tool) is MUCH
FASTER than making coax connections, if speed is important.
Of course, the better (best?) approach is 10baseF, but it isn't readily
available for us with home installations (at least not at the price *I*
want to pay.)
Gary
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