[Nut-upsuser] CyberPower usbhid-ups continuously disconnects/reconnect

[SirG]

I have had a similar problem to many other people for the last few
months with my Cyberpower UPS. It was working properly after reboot
about one in five times; the rest of the time it  would endlessly
disconnect and reconnect, according to syslog messages.

The latest I was able to find towards a solution is
http://www.mail-archive.com/nut-upsuser@lists.alioth.debian.org/msg06671.html

The root cause is identified as a Cyberpower firmware behavior, that
disconnects the box, unless a driver claims it within 20 seconds of
connection. Since the driver is started by an rc script only at boot,
if that boot script does not run at the right time, the only recovery
is to run 'upsdrvctl start' manually - which is what I had been doing.

The suggestion in the above article is to re-arrange the boot scripts
to have nut start earlier.

In my case this was a bit harder to control (Ubuntu uses upstart) and
did not seem very robust; I came up with an alternative solution for
systems that use udev.

The solution is to have udev run 'upsdrvctl start' when this device
connects. To do so, add ", RUN+="/sbin/upsdrvctl start" to the end of
the udev config line for your device. Mine looks like this:

#  Dynex DX-800U?, aloso 825AVRLCD  - usbhid-ups
ATTR{idVendor}=="0764", ATTR{idProduct}=="0501", MODE="664",
GROUP="nut", RUN+="/sbin/upsdrvctl start"

In Ubuntu, the recommended way to do this is described in
/etc/udev/rules.d/README. I  copied
/lib/udev/rules.d/*-nut-usbups.rules to
/etc/udev/rules.d/nut-usbups.rules and modified my device's line as
shown above.

Works like a charm, very stable, and, as a fringe benefit, I can
hotplug my UPS, if I need to rearrange my USB cables.

HTH,

---SirG