Re: Insulating D-shell from chassis?

I've been reading in these posts for some time now about ground-loop
problems in logic level interfaces.

This just should not be a problem.

I have a gut feeling that isolating a DB Connector is just masking an
underling problem that could be a hazard to equipment and user, and
the stepping problem will come back when least expected and least
needed.

Gound-Loops are typically only a few millivolts in high impedance
lines such as line level audio systems. TTL Logic is usually pretty
clean where improperly designed CMOS Logic Lines could be more
susceptible.

I would suspect a poor ground or wiring problems somewhere in the AC
Lines.
It might be advisable to have an electrician to dig into if and why
there is such a large potential difference between your CPU and
Controller Chassis.

Also, Avoid RS232 and Parallel lines that are longer than needed.
When I need to use RS232 in long or noisy environments, I'll use
RS232 to RS485 Converter modules on both ends.
If possible, use the same power outlet for all equipment.

Any engineers out there that can comment on proper line loading for
long Logic Level Lines?

Tom M.