Guido Tedeschi wrote:
<div class="moz-text-flowed" style="font-family: -moz-fixed">You can
also build this simple optocoupled interface:
http://www.hamlan.org/tech/k2optocat/k2optocat.htm
That might have a use in relation to the KAP100, but it doesn't address
the current problem, and doesn't make sense for the KIO2.
It doesn't solve the problem because it protects Auxbus by by simply not
connecting it to the cable on the outside of the KA2, leaving the signal
vulnerable to the insertion of an incorrect cable into the connector on
the KA2 itself.
It doesn't make sense for the KIO2, because the purpose of that is to
generate bipolar voltages and level shift to them, the former being done
to ensure that the full RS232 specification is met, rather than the weak
compatibility achieved by stealing power from the fully conforming
equipment on the other end of the cable. This interfaces steals power
for the actual RS232 drivers, and in a way that basically treats the
RS232 inputs as current loop operated, rather than bipolar voltage driven.
In my view, if one wanted to opto-isolate the RS232 signals, the right
way of doing this is to interface on the control board connector, and
completely replace the KIO2.
--
David Woolley
Emails are not formal business letters, whatever businesses may want.
RFC1855 says there should be an address here, but, in a world of spam,
that is no longer good advice, as archive address hiding may not work.
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