[Nut-upsdev] Documenting the NUT driver-qualification process

Ted Mittelstaedt tedm at mittelstaedt.us
Thu Jul 10 07:39:50 UTC 2014

On 7/9/2014 4:16 PM, Charles Lepple wrote:
> On Jul 9, 2014, at 11:24 AM, Ted Mittelstaedt<tedm at mittelstaedt.us>
> wrote:
>> Someone could write a driver for MODBUS for NUT, all of the
>> information and materials are available to do it.  The simple fact
>> of it is that the reason no one has done so is that the apcupsd
>> program is available.
> You're right, it's the microlink protocol that they have been
> promising to release. My mistake. We even have a branch where Arnaud
> was starting to write some code against libmodbus.

Why don't you just lift all the APC modbus code from the modbus
module in apcupsd?  The work is already done there.

> However, the
> documentation seems to lag the introduction of the new products that
> all of a sudden don't work with existing software.

The Modbus doc for APC UPSes is here:


>> I guess the story about the big evil impersonal corporation beating
>> up on the small OSS software project is more compelling than the
>> reality that the big corporation has made development info
>> available and the small OSS software project isn't interested, even
>> though the story is fabrication.
> Sigh.
> A simple "that's wrong; here are the facts" would have sufficed.

Your correct, my apologies!

> I did try to look up the correct information this morning, and I was
> getting 503 errors on apcupsd.org, and APC's forums were timing out.
> My point, which I believe still stands, is that Tripp Lite has been
> implementing the standard PDC HID protocols, and even testing against
> NUT, whereas APC has been much more of a moving target. I don't
> believe I accused APC of malice in their innovation, but if it sounds
> like I am frustrated with that situation, I am.

I understand the frustration! I noisily complained on the apcupsd forum
for several years about the situation.

Now I'm noisily complaining on the NUT forum about the situation. ;-) 
Fact is I use both apcupsd and NUT.

Anyway, APC is under the impression that NUT is sponsored by MGE/Eaton.
So, it interests me to read:

"..Today, the tables are turned: MGE/Eaton have decreased their 
involvement in NUT.."

If APC shipped a SMT UPS to you with MODBUS loaded on it would you 
develop an APC module for NUT?

> When you're done picking apart Eric's UPS HOWTO, we have plenty of
> NUT documentation that could also stand to be updated. Patches gladly
> accepted. I'll even reformat them to Asciidoc if that's not your cup
> of tea.

OK I suppose I deserved that. ;-)   But Eric's a writer also and he 
should know how tempting it is to dangle a piece of ripe fruit like that 
in front of one.

I'll review the NUT docs.  What do you want them in?  My preferred 
editor for textfiles is vi.  I'm a minimalist.  I subscribe to the
notion that those who can write, write.  Those who can't, reformat 
documents with WYSIWYG.


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