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

[Tom Li]

On Wed, Dec 01, 2021 at 08:39:39AM -0500, Greg Troxel wrote:
> 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:
> 
> 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.

There seems to be a misunderstanding here. The original proposal doesn't
change ups.status=OL at all. Instead, it merely appends an additional
keyword "ECO" after "OL", i.e. ups.status="OL ECO". Since ups.status
is already a space-separated list of keywords [1]. It doesn't involve any
breaking change, everything will continue to work as usual.

Instead, the motivation of using the keyword "ECO" is to maintain the
existing behavior - I looked around the codebase and found some drivers
[2] already use the flags "OL" & "ECO", so I thought it was a good idea
to simply make it a documented and standard behavior.

[1] Currently we already have "OL", "OB", "LB", "HB", "RB", "CHAG",
"DISCHRG", "BYPASS", "CAL", "OFF", "OVER", "TRIM", "BOOST", "FSD",
and a huge number of possible combinations.

> Therefore, I suggest a new variable that describes the form of online
> behavior, choosing among
> 
>   inverter
>   bypass
> 
> and maybe something else

[2] I rechecked and found it was actually only used by a single driver, so on
second thought, maintaining the existing behavior is not really a concern, so
I agree, a new variable can be an alternative solution if there's consensus.

Cheers,
Tom Li