[Nut-upsdev] 答复: I love NUT

Ted Mittelstaedt tedm at mittelstaedt.us
Tue Apr 28 19:19:34 UTC 2015


This is a common issue in technology when you have complex products
that the majority of consumers of those products do not understand how 
they operate.

If most UPS customers understood the importance of standardization they
would have refused to purchase non-standard UPSes and all UPSes would
have long ago standardized on a single management protocol.

The normal thing is that product manufacturers do not want standard
commodity products.  They want custom, specialized products.  That 
creates customer lock-in.

With simple products - like a toaster or a gallon of milk - the consumer 
thoroughly understands what they are buying - and most of them will not 
buy a product that significantly differs from the standard.
They do not want to buy a toaster that only toasts 1 bakery's bread.

With complex technical products consumers are easily fooled, and all the 
manufacturers need to do is create the appearance of similarity and 
consumers think they have a choice when in reality they don't.

When you buy a car for example and 3 years later it needs a new 
alternator - you will rapidly find that there's no standardization on
alternators, so you will end up paying a very large amount of money
for a replacement.  that benefits the manufacturer, not you.  No car 
consumers are demanding that cars use standardized parts like alternators.

In many markets the government gets involved and enforces some 
standardization, that's why for example most cars are the same width
in size, have turn signals, and headlights.  But, that standardization
does not generally help the consumer.

The other issue is refinements of products cost a lot of money to 
develop.  So manufacturers have to pay for them by higher prices, and a 
commodity market cannot support prices high enough to pay for 
innovation.  That's why, for example, a gallon of milk hasn't changed 
much over the last 30 years.

And, in this vein, refinements cannot be used/stolen by competitors 
until the cost to develop them has been paid for.  Thus the need for 
patents, and you cannot patent something that has prior art (well you 
can but you won't be able to defend it)

UPSes are complex technical products that are not understood by most 
people who buy them.  Consumers may demand the lowest price on a UPS
but the only market where there is any significant competition in UPSes
is the non-managed UPS market, the so-called "desktop" UPSes that are
500va or less with runtimes of less than 5 minutes, fully loaded.  With
more expensive UPSes, other factors than marketing against a competitor
are more important.

Some of these factors are:

Protocols like APC's UPSLink predate USB Power-HID

USB Power-HID also does not carry all datapoints that a UPS maker may
want to make available

Older mainframes did not have USB only Serial.  A modern UPS maker may
want to produce new UPSes that work with older equipment.

There is no public standards-body standard for UPS data.  Only a 
de-facto standard.

Backwards compatibility is huge - people run older software quite a lot
in industry.  New devices need to be compatible with older software, 
this is a barrier to dropping support for older/superseded protocols.

not everything protected by a UPS is a PC.  An industrial machine like
a 3D printer may only use a set of contacts to signal a trigger of
a shutdown sequence.

UPSes also depreciate an enormous amount.  You can easily find 3-4 year 
old UPSes on the secondary market selling for very cheap, and they
still work fine since power standards have not changed.  That tends to 
create large market inertia to changing protocols.


On 4/28/2015 6:17 AM, Carsten Burkhardt wrote:
> Dear Developer and Tester,
> I love NUT, because of the great interoperability. So I have the choice
> and freedom on the operating system or the device. Many thanks on all
> developers and the manufacturer, they support with informations,
> material, wages and so on.
> Dear Hyouko,
> I am interested in to know, why every manufacturer use their own protocol.
> The USB Power Device protocol is already 20 years introduced. In my
> opinion a unique protocol is easier to handle. Just to use one protocol
> makes the soft- and hardware more efficient, reliable, sustained… What
> is your opinion or you know the reason why everybody makes their own?
> http://www.networkupstools.org/protocols/powercom/Software_USB_communication_controller_SKP_series.doc
> Sincerely Carsten
> Am 23.04.2015 um 02:57 schrieb κΰ(bluefish_wei):
>> Dear Hyouko,
>> Thank you very much !
>> Best regards,
>> Bluefish
>> -----邮件原件-----
>> 发件人: hyouko at gmail.com [mailto:hyouko at gmail.com]
>> 发送时间: 2015年4月23日 7:25
>> 收件人: 魏伟(bluefish_wei)
>> 抄送: nut-upsdev at lists.alioth.debian.org
>> 主题: Re: [Nut-upsdev] How to upload new ups driver to NUT
>> 2015-04-21 8:23 GMT+02:00 魏伟(bluefish_wei)
>> <bluefish_wei at voltronicpower.com.cn>:
>>> Can anyone tell me how to upload new ups driver to NUT website ?
>> You can either open a pull request/create a new issue on GitHub [1] or
>> send a gzipped patch to this list.
>> A quick read of the developer guide [2] should make it easier to get
>> the code merged faster and to avoid possible problems.
>> Also, documenting the protocol behind your driver [3] goes a long way
>> in making it easier for others to support it and effectively extends
>> its life.
>> As we are here, since you appear to be working for Voltronic Power,
>> I'd like to take the chance to ask if it's possible for you to release
>> (and give us permission to redistribuite) the protocols adopted by
>> your various devices (present and past): we have already done some
>> work [4] and support for P15/P16/P30/P34/P35/P36 protocols is under
>> way, too.. but we still lack some information and, obviously, knowing
>> the protocols in full directly from the manufacturer would be a lot
>> better (not to mention the huge amount of time I would save in reverse
>> engineering...).
>> [1] https://github.com/networkupstools/nut/
>> [2]
>> http://www.networkupstools.org/docs/developer-guide.chunked/index.html
>> [3] http://www.networkupstools.org/ups-protocols.html
>> [4] http://www.networkupstools.org/ups-protocols.html#_voltronic_power
>> _______________________________________________
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>> http://lists.alioth.debian.org/cgi-bin/mailman/listinfo/nut-upsdev
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