Nut upsdev - Dec 2021 - Proposed discussion: standardization of Status Flags and Instant Commands for ECO mode

Hello all,

  In issue https://github.com/networkupstools/nut/issues/1201 a point was
raised recently by the author of modbus drivers for Huawei devices, that
while many online UPS systems support ECO mode (where the mains output
bypasses the UPS during normal operation, and is only handed over to the
UPS automatically during a power failure), it seems this is not currently a
concept in NUT data/state model.
> The basic standardization items needed are:
   1. A ups.status flag for ECO mode, currently there's no standard. I
   looked around the codebase and found many drivers already use the flag OL
   ECO, so I think we could settle on that.
      - But with a caveat - the ECO status flag only appears when the UPS
      is online, and can disappear when it's on battery. But this is
how many UPS
      units report the current power status - the register only has a value for
      "online ECO", not "battery ECO" (which is
understandable, since
it doesn't
      really make sense).
   2. Instant commands for entering and exiting ECO mode. Currently NUT
   doesn't have standardized instant commands for that.


  Does the esteemed NUT developer community have some constructive opinions
and ideas about this? After all, naming is one of the hardest problems in
Computer Science ;)

Thank you all in advance,
Jim Klimov
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Doesn't this amount to changing ups.type from online to offline?

Jim Klimov via Nut-upsdev <nut-upsdev at alioth-lists.debian.net> writes:
>> The basic standardization items needed are:
>
>    1. A ups.status flag for ECO mode, currently there's no standard. I
>    looked around the codebase and found many drivers already use the flag
OL
>    ECO, so I think we could settle on that.
>       - But with a caveat - the ECO status flag only appears when the UPS
>       is online, and can disappear when it's on battery. But this is
> how many UPS
>       units report the current power status - the register only has a value
for
>       "online ECO", not "battery ECO" (which is
understandable, since
> it doesn't
>       really make sense).
>    2. Instant commands for entering and exiting ECO mode. Currently NUT
>    doesn't have standardized instant commands for that.
>
>   Does the esteemed lNUT developer community have some constructive
opinions
> and ideas about this? After all, naming is one of the hardest problems in
> Computer Science ;)u
My view is that whether a device is in some true online mode or ECO mode
is a minor implementation detail.  I would not want to overload
ups.status for this, because many data consumers want to know which mode
we are in:

  utility power is ok and being used to power the load

  the battery is being used to power the load

I can imagine software out there that doesn't know about the ECO
concept, and it should continue to work.  That requires not changing
ups.status=OL.



Therefore, I suggest a new variable that describes the form of online
behavior, choosing among

  inverter
  bypass

and maybe something else, describing if the  UPS is running a full-blown
inverter, just wiring input to output, or doing something else.   (I
dimly remember BEST Ferrups which have some intermediate "line
interactive" mode with ferroresonant transformers.)    This might be
empty when offline, or it might be the same, especially for units that
only have one possibility.

Then, given a ups.mode that shows these choices, that could be set to
command which mode is chosen, when there is an ability to choose.

UPS units that only have inverter or bypass could have the variable
basically read only.


People/programs that care can look at the new variable, and those that
don't can continue as they are with no problems.


Personally I am using a Best Fortress LI660, which I think is ~always in
eco mode, as it's much quieter than when on battery and I hear a relay
when it transfers.   I don't think it has a non-eco mode.   But really
my software  wants to know if the power is ok or not to report to home
assistant, and the remaining runtime, battery voltage, etc.

Greg
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