[Nut-upsdev] Liebert ESP II driver

[Farkas Levente]

On Tue, Jul 6, 2010 at 21:53, Arjen de Korte <nut+devel at de-korte.org> wrote:
> Citeren Farkas Levente <lfarkas at lfarkas.org>:
>>>> I use my ups with usb -> serial converter.
>>>
>>> Which one?
>>
>> anyone. since the usb-serial converters use in this way. and with this
>> patch both the serial and the usb-serial connection works.
>
> Still we want to know which USB to serial converter was used. We regularly
> get questions which USB to serial converter to use. I know that *some* will
> not work with *some* drivers (usually because the added latency is more than
> the driver author anticipated years ago). However, if we know which ones
> *do* work with a certain driver, that's useful information.

 ID 067b:2303 Prolific Technology, Inc. PL2303 Serial Port
but on _all_ usb-serial converter one read only read on byte while on
the serial cable one read can read a byte array if there are more date
available. that's the main difference.

>> in it's present state the liebert ups has an internal settings. and it's
>> by default (ie. if nut's liebert-esp2 driver do not set it otherwise) if
>> the ups plugged off the input then it _immediately_ send a "LOW BATTERY
>> EVENT".
>
> How does one change this setting? So far, we don't have instcmd's for this
> driver, simply because we don't know what to tell the UPS to change
> settings. But if you know how to change settings on the UPS, I'm all ears.

we just try to debug what happened with liebert's own java
driver/service and what not with nut. but it'd be useful if some nut
expert can help us to identify the difference and find more easily and
faster the reason.

>> in response to this nut shutdown the host computer and after 120
>> second turn off the liebert ups itself.
>
> Is this a fixed time interval after power failure, or is this a triggered by
> the UPS detecting that the load has switched off (aka battery saving mode)?

the truth is that we don't know what's happened. we only recognize if
nut is running and we just unplug the power from the ups the computer
shutdown and after 2 minutes the ups turn off itself.
while if we run liebert's java ups manager service and java gui the
same thing is not happened.

>> so in the present state if nut with liebert-esp2 running on any computer
>> with liebert ups even if the battery if fully charged the host will
>> shutdown immediately.
>
> Not necessarily. You always have the option of increasing FINALDELAY a bit.
> Of course the system *will* go down on every power failure, but at least it
> will give you a little more runtime.
>
>> for me it means currently nut's liebert-esp2 worse then liebert without
>> nut.
>
> Until you're hit by a power failure when you're not around to shutdown your
> system(s) in time. In my opinion, a system that solely relies on a UPS to
> provide power in case the mains fails (ie, without a generator that kicks in
> after a few seconds) but doesn't monitor it, is only marginally better than
> not having a UPS at all. It will give people a false sense of security.

i mean currently even a few second outage cause a shutdown which is
worse then not connecting the system to the ups.


-- 
  Levente                               "Si vis pacem para bellum!"