John Goerg <john at krwc1360.com> writes:

>  > David Dyer-Bennet wrote:
>  >So, on the connections -- I've tried connecting pin 20 (DTR; light
>  >showing red for negative voltage) to various things both direct and
>  >through a 4.7k resistor.  I've also tried grounding the other things
>  >(to pin 7, SG).
> 
> The way I see it you could use pins 5,6,8 (db-25) for monitoring,
> being they all set above ground.  Your open collector outputs on the
> ups will take these to ground on a state change.  But does your
> computer need to see a rs-232 low ( that is negative) to register a
> change?  Your ups can't do that directly. Jumpering 5 or 6 or 8
> directly to 20 will do this. See if that works for your program as a
> test.  You also mentioned it worked once, did you mean the program the
> first time you run it?

Jumping 5 or 6 or 8 to 20 doesn't do anything (other than lighting the
light associated with 5, 6, or 8 on the breakout box).  But it isn't
detected either by my program or by the UPS monitoring programs I've
tried. 

When I run my monitoring program it reports one value, then instantly
another value, then never reports a change again.  The initial change
is *before* I do anything to make a change at the breakout box.  It
very probably represents some sort of bug in the program, possibly
even a bug that makes the whole test invalid; I just haven't figured
out what it *is* yet.

If I control/c out, and then run it immediately again, I get exactly
the same behavior (and exactly the same values), which I take as
additional evidence that the output isn't responding to reality.
-- 
David Dyer-Bennet, dd-b at dd-b.net  /  New TMDA anti-spam in test
 John Dyer-Bennet 1915-2002 Memorial Site http://john.dyer-bennet.net
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