1. Meters in EMAN
Bruce Nordman
March 28, 2013

2. Issue
If power to a device (load) is measured by a meter, then there is a wire from the meter to the device
There may be other devices in between that are not known to the EnMS and may not implement EMAN
E.g. ircuit breakers, PDUs, UPSes, other meters
Individual loads could all report a direct wired connection to the meter; this works
Some building owners may be reluctant to imply the direct wired connection
Because of existence of other intermediate hardware

3. Proposed Solution – ‘Clouds’
A ‘cloud of wiring’ can represent the unknown devices
The cloud can be represented in the both the relationships model and the power interface model
NO power/energy data would be reported by a cloud — only connectivity
Typically the cloud would be implemented by the EnMS itself
Cloud UUIDs installed into loads, meter device

4. “Clouds” - relationships
Meter
Load
Load
Load
Loads have a powered-by relationship to cloud
Cloud has a powered-by relationship to meter

5. “Clouds” – power interfaces
Meter
Load
Load
Load
Loads wired to output of cloud
Meter wired to input of cloud
NO POWER DATA reported at cloud interfaces

6. More complicated scenarios possible
Meter
Meter
Load
Meter
Meter
Meter
Load
Load
Load
Load

7. Conclusion Directly represents actual wiring context
Is flexible to varying topologies
Works for both relationships model and power interface model
Eliminates need for “metered-by” relationship
EnMS simply traces up from each device to see all upstream devices that can measure power
A meter is just a device that consumes no power itself
This is just use of existing model
NO changes to UML or MIBs