G'day,

I'm trying to figure out the interface pinout for a uninteruptible
power supply (UPS) that I have.  The unit came with no documentation,
and no interface cable, and I suspect that the cable may require some
pin remapping anyway.

If you are willing to help, I've drafted a schematic of the circuit in
the UPS attached to the DB9.  I've not gone beyond the optocouplers; I
got rapidly lost.  I've also taken a few snapshots of the PCB.

        <http://quozl.netrek.org/p600v/> (220k of images)

The UPS is straight analog; there are no digital components on the
PCB, no crystals, no microcontrollers (sadly), just bog standard
things like LM339's.  I suspect therefore that the signalling from the
UPS to the PC is just "online" and "low battery", via modem status
lines.  But there's a twist; there is an optocoupler facing the other
direction.  I can't figure out what function it has.

--
James Cameron    mailto:quozl@us.netrek.org     http://quozl.netrek.org/

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