[Nut-upsdev] oneac driver patch

Jacob Schmier j.schmier at live.com
Fri Feb 29 23:04:03 UTC 2008

On February 29, 2008 2:56 PM, W. Keith Miller <keith.miller at stonebranch.com>
> I have a V96 and have access to a V92 ON series UPS.
> I can tell you right off the oneac drivers don't see the 
> family OZ with which V96 responds with.  

The oneac driver in the trunk of the NUT (Network UPS Tools) should see the
'OZ' family.
You can see the changeset here:

> I'd be willing to 
> help out with this driver as I have a data center full of 
> them plus one at home. However my C is weak.

What OS are you using NUT on?

Can you communicate with the Oneac UPS using MopUPS?
You can download a trial version here:

Here's how I did it:

I did most of my development/investigation on Linux.  When my Oneac UPS
wouldn't work with NUT, I noticed that the UPS was responding with 'OZ',
even though it was an ON series.  This is why I patched the driver.

I connected the Oneac UPS to MopUPS (the program Oneac told me to use) and
looked at the data being passed to/from the UPS over the serial link (strace
-x -e trace=open,read,write,close -p <pid>).  I saw that MopUPS was writing
a few specific characters to the UPS that got a response ('%', '^', and '&'
characters).  Next, I either modified the oneac driver for NUT or wrote my
own application (can't remember which) to send these characters and I
printed the responses.  I found an ONEAC protocol doc on the NUT website
(http://www.networkupstools.org/protocols/oneac.html), but it is a bit old.
Someone from Oneac, I won't say who, confirmed to me that this protocol is
over 10 years old and only partially supported today.  I don't know exactly
how much of the protocol is still supported and I don't know what additional
data the UPS is sending when it responds to the queries.  Since the
communication protocol is all ASCII, I figure it can't be too hard to figure
at least some of it out.  

I don't have the Oneac UPS in my possession anymore, so I can't do any
further work on this driver.  I hope you find this information useful.


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