OT: OpenServer 6 compatible UPS units

Can anyone tell me which make/model of UPSes that I can successfully
use with SCO OpenServer 6? I have been successfully using Tripp Lite
SMART 1500LST units and their Power Alert 12.4 Java-based software.
However, for some reason, they switch the unit and it no longer
detects the UPS on the server. Spoken with Tripp Lite support and
they will be replacing it. However, it take 3 weeks (too long for a
server???)

What make/models can anyone suggest, that the monitoring software
works?

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