APC-UPS serial cable stops boot

From: Eric Zager (zager_at_remove-hostname.idapps.com)
Date: 10/22/03 

Date: Wed, 22 Oct 2003 17:01:34 -0000

I was starting to try out nut-1.2.1 on OpenBSD 3.3 with my APC UPS.
Yes, I know support of APC products is difficult because they don't
publish specs. But I'm running into a problem earlier in the process.
If I have the cable 940-00950A plugged into the serial port, then the
OpenBSD boot process stops at "setting tty flags." If I unplug the
cable, boot continues. I'm not sure the cable even has to be plugged
into the UPS. From the little research I've done, that cable ties
DCD to DTR, and RTS to CTS. Is there a workaround? It sounds like
nut doesn't care about those lines, so I could just make a cable
without those loopbacks.

Thanks for any suggestions,

- Eric