Re: [eman] eman framework issue: How to model a meter?

[Brad Schoening <[e-mail]>]

Juergen,

My experience has been that usually a meter was just a meter.  While many
devices such as PoE switches and PDUs can internally meter, we have to
recognize that there is a real use case for stand-alone metering.
Intelligent smart meters from vendors such as Shark, SATEC, and Crompton
are but a few examples of these widely used products   An ethernet switch
is a device who's primary purpose is networking, but may have metering
relationships.  But a smart meter is a device with the primary purpose of
metering.  
 

A common sense approach to classification should be more than adequate to
distinguish between products which consume energy to provide some
function, products that primarily produce energy, and products which are
designed for metering.  If we clarify that classification should involve
the primary purpose of a device it would this address this nit?

You ask "Do we need to model metering capability at all"?  Yes, because
smart meters, in particular sub-meters, are a key part of real time energy
monitoring.

Regards,

Brad

On 8/20/13 1:09 AM, "Juergen Quittek" <[e-mail]> wrote:

>Dear all, 
>
>Here is another framework issue: How to model metering capabilities of
>devices?
>
>Our framework draft (draft-ietf-eman-framework-08) models metering
>capability by categorizing devices and components into either a producer,
>a comsumer, a meter, or a distributor, see pseudocode on page 43.
>
>I think this approach is broken. It may be useful for modeling simple
>scenarios, but it does not work as general model.
>
>There are two problems with this approach.
>
>1. The either-or classification. A meter is typically not just a meter,
>but as well a consumer that consumes energy when doing it's job. A PDU
>that meters power at it's outlets is a meter and a distributor and a
>consumer. The same holds for a PoE switch. These are not either meters or
>consumers, they are meters and consumers and some of them are also
>distributors at the same time.
>
>2. The categorization as 'meter' is only available for devices and
>components, not for power interfaces. But obviously a device with
>metering capabilities meters at (some of) its interfaces. Take the PoE
>switch that meters power at some or all of its PoE outlets. It would be
>natural to label the power interfaces at which metering capabilities are
>available as 'metered'. It appears strange to classify the device as
>'meter'. 
>
>The basic question here is: Do we need to model metering capability at
>all?  If yes, we should model it as an attribute, not as a category; and
>we should model it as attribute of the power interfaces as well.
>
>BTW, if we model metering capability (monitoring), we should consequently
>model circuit breaker capability (control) at power interfaces as well.
>
>Cheers,
>   Juergen
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