15 Jun
2012
15 Jun
'12
4:59 a.m.
(2) I've
even seen one device which powers down its transmitter
unless it sees at least one input pin being driven. [...]
I assuem it also powers
down the drivers for any flow control
outputs. That is plain evil. What device does this?
As I said above, I don't recall enough details, except that I think it
was a battery-powered device.
A third thing you cna't test with the light
adapter on its own is an
RS232 drvice that's powered from the RS232 signals,
True.
I think it's fair to say that no solution works in
_all_ cases. That
doesn't mean the LED adapter is not handy to have around. It works
in enough cases that it's a useful thing to have in the toolkit.
Agreed on all three points. I brought up these cases not to say "don't
bother with a LED RS232 breakout box", but more "be aware of these
possibilities when debugging, so that you don't, for example, jump to
the conclusion that because no lines are driven the hardware must be
fried".
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