[Nut-upsdev] NUT I-D: Minimum command and variable set for conformance

Manuel Wolfshant
Mon, 03 Jan 2022 12:06:03 -0000

On 1/3/22 13:47, Roger Price wrote:
> I received a comment calling for a minimum command and variable set to
> be supported for conformance.
>
> The proposal assumes that in the future there will be UPS units which
> natively include an Attachment Daemon and which support direct
> internet access from a Management Daemon.? Something like figure 3 in
> section 3 of the I-D:
>
https://www.ietf.org/archive/id/draft-rprice-ups-management-protocol-05.html#name-ups-and-attachment-daemon-i
> Such a UPS could claim to be RFC compliant, a marketing advantage, and
> the comment is that such a claim should require that at least a useful
> subset of the commands be implemented.
>
> The comment proposes as the minimum set: ? Battery state
> (charging/charged), UPS on main power/UPS on inverter, battery
> percentage of charge left, and killpower (commanding the UPS to turn
> itself off) at the least. ?
>
> The idea of a minimum command and variable set seems to me to be an
> interesting idea, but we need to look closely as what is involved.
>
> 1. An Informational RFC cannot lay down conformance standards, but can
> discuss a "Recommended minimum support for commands and
variables"
>
> 2. The minimum set is for a consumer grade appliance. Professional use
> requires much more to manage for example unattended servers.
>
> To encourage discussion, I propose the following new subsection 9.4
> Recommended Minimum Support:
>
> ?9.4 Recommended Minimum Support
>
> ?The features provided by current UPS units vary widely.? However
> experience
> ?shows that a minimum feature set is needed for satisfactory use of
> the NUT
> ?Project software.? For a full list of variables see the Recording
> Document
> ?(7.1).
>
> ?9.4.1 Desktop PC Variables
>
> ?The following variables form a minimum set suitable for Desktop PC.?
> It is
> ?expected that on public power supply failure, the PC will be halted.?
> It will
> ?not restart automatically when power returns.
>
> ?battery.charge
> ?battery.charge.low
> ?device.mfr
> ?device.model
> ?ups.status with statuses OL OB LB FSD
>
> ?9.4.2 Unattended servers, additional variables
>
> ?The following additional variables are needed in a minimum set
> suitable for an
> ?unattended server.? It is expected that on public power supply
> failure, the
> ?server will be halted.? It will restart automatically when power
> returns.
>
> ?battery.date
> ?device.serial
> ?ups.delay.shutdown
> ?ups.delay.start
>
> ?9.4.3 All systems
>
> ?Satisfactory use of the NUT Project software requires support for all
> commands.
>
> All comments welcome.? If the list is agreed, I will add the new
> subsection 9.4 "Recommended Minimum Support" to the I-D
>
> Roger

A few comments here

- I have not seen any low- and mid-end UPS that knows about killpower so
not including it as a requirement is a good idea

- The 3KVA Ablerex that I have handy and which powers since ... a long
time ago ( I've replaced 3-4 times the batteries, at least ) a small
size DC does not know about battery.date and since it is connected via a
Serial-to-USB adapter, I am not sure that it knows about device.serial.
It probably does, but in lsusb -v I can only see the USB adapter

wolfy