[Nut-upsdev] Request to add new nut variable to get device part number

[ChetanAgarwal at Eaton.com]

> Have a look at the following list of variables that we already
support:
> 
>      (device|ups).model
>      (device|ups).mfr
>      (device|ups).serial
>      (device|ups).type
>      (device|ups).firmware
>      (device|ups).firmware.aux
>      (device|ups).id
> 
> 1) In what way is the suggested new variable name different from the
> ones above?


Device Part number is unique for all the devices and will help in
identify the device. This is provided by the manufacturer for the
particular device. 
(device|ups).id seems to be relevant, but I guess, it is the identifier
for the device which can be r/w; and will be different for two devices
with same part number. 

device.part can be a read-only value read from the device wherever
supported / applicable.  

I was looking into BCMXCP TODO List and found part number as a value
provided in the Config Block.

As per XCP Protocol document, 
---------------------------------
5.2 Identification and Configuration
The UPS must have a way of reporting its Identification and
Configuration information, including:
* Model name (must not have Manufacturer in the text)
* VA rating
* "manufacturer"
* Serial and model or CTO numbers
* Customer-set identification string
* nominal input and output volts, amps, VA, power, and frequency
* Identification of submodules: version, name or part #
---------------------------------

device.part can be useful for identifying the ups.

> 2) Why do we need to be able to access this remotely?
> 
> NUT is not an ERP system.
> 
Part number is present for almost all the devices and can help identify
the model and other details using the part number. 

Best Regards, 
Chetan