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Application #4 - energy usage sub-metering, Ontr ls o, Application #4 — energy usage sub-metering – Contemporary Control Systems BASremote Application Guide User Manual

Page 8: Application guide — basremote

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AG-BASR0000-BC0

Page 8

Application Guide — BASremote

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CONTEMPORARY

Application #4 — Energy Usage Sub-metering

The BASremote Master can be used as a data

concentrator for sub-metering applications. With

sub-metering, tenants can be billed a portion of the

actual energy usage based upon individual usage.

Sub-metering can also verify actual energy savings

from “green” initiatives. Usually a pulse is generated

from natural gas, water, or electrical meters which need

to be captured and accumulated in order to determine

energy usage. One pulse represents a unit of energy

usually requiring a scaling factor to be applied. The

BASremote Master can be configured through web

pages to handle up to six pulse inputs with independent

threshold settings in order to adapt to different styles of

meters. For convenience, both pulse rate (power) and

accumulation (energy) can be displayed on a

BASremote Master web page after applying a

meaningful scaling factor to the raw data. Sedona

Framework can also be used to calculate beyond simple

scaling. Internally, pulses are accumulated indefinitely

until reset by a supervisory controller or through a

protected web page. Pulse data cannot be lost due to

inadvertent power loss because it is stored in nonvolatile

memory. If special energy demand monitoring is required,

this can be accomplished using a Sedona Framework

program in the BASremote Master or with a program in a

supervisory controller.

The more sophisticated electrical meters have a

Modbus Serial interface which can be attached to the

BASremote Master MB port. Using either the router or

gateway functionality of the BASremote, energy usage

data can be presented to a supervisory controller over

Ethernet.

Application #5 — Power over Ethernet (PoE) for a “One Cable Solution”

The Power over Ethernet standard (IEEE 802.3af) gives

the system integrator another opportunity to be

imaginative. With PoE, both 48 VDC power and Ethernet

communication reside on the same cable. PoE power is

derived from Power Sourcing Equipment (PSE). This

could be an Ethernet switch, a multi-port mid-span PSE,

or a single-port PSE commonly referred to as a Power

Injector. Regardless of the PSE, the BASremote PoE

performs the duties of a Powered Device (PD) in that it

can still communicate over Ethernet while powering its

own electronics plus any devices connected to its auxiliary

24 VDC power supply. The BASremote PoE has identical

capabilities as the BASremote Master but without the

need for a power input connection. By using an

uninterruptable power supply (UPS) at the PSE source, it

is possible to guard the BASremote PoE against any

power failures. This arrangement could be attractive in

critical control or security applications.

EIPE PoE Injector

Simply make a connection from a

PoE compliant device to the

Ethernet port on the BASremote

Saves from purchasing proprietary

BAS cabling and the associated cost of

installation. May gain you points toward

“green certification”.

Both the BASremote and

field devices can be

powered from the data cable

One-Cable Solution

Data & Power on One Cable

Power Over Ethernet

BASremote Master PoE