[Nut-upsuser] CyberPower 1500AVRT won't load driver!

Charles Lepple clepple at gmail.com
Wed Nov 28 06:43:26 UTC 2007

On Nov 27, 2007 10:11 PM, Richard Chapman <rchapman at aardvark.com.au> wrote:
> I can't really help - but have a similar problem with a different UPS. I
> have a Belkin ups with belkinunv driver which claims to support my
> model. I get a different error - but essentially the same issue. It just
> doesn't seem to get anything back from the UPS on ttyS0.

Try running the driver directly with "-DDD" on the command line, and
copy-and-paste the error messages. (Also, please change the subject to
match your driver.)

> I have checked
> the permissions on ttyS0 and they appear correct. I find this a bit
> puzzling - because I can't figure out how these permissions got set. How
> did it know that I wanted to use ttyS0, apparently before I ever told it
> what port to use?

A little more detail would help here. In some cases, the permissions
are what your distribution would normally use for the serial ports
(e.g. group "uucp").

What does "ls -l /dev/ttyS[01]" show?

> I also have only one physical serial port on the box - though the device
> manager reports 2 16550 ports. I can't really find a way to definitively
> prove that the port on the back is ttyS0 - so any ideas how to do this
> would be appreciated. Are there any settings that can be set for ttyS0,
> such as baud rates etc, and if so - how is this done? I am relatively
> new to Linux - so pleas be gentle with me...:-)

I am fairly certain that each individual driver sets the baud rate if
necessary - although some drivers have options to pick one of several
baud rate options if the hardware supports multiple rates.

Often you will see a change in the output of "statserial /dev/ttyS0"
after you plug a device into that port. (No guarantees, since some
UPSes use simple signalling that does not show a difference in the
status until the power fails, or the battery goes low.)

- Charles Lepple

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