dlms/cosem - how to make it simple - smart … kmethy.pdf · dlms/cosem - how to make it simple gy...

Metering Europe 2005 Barcelona 1

DLMS/COSEM -How to make it simple

Gyızı Kmethy

DLMS User Association


Energy /

demand

Load profile

s

Quality /

Monitorin

g

Value Added

Services

Tariff /

load

scheduleAccess

control

DLMS messaging services

COSEM Application layer

OSI / Internet lower layersProtocol data units

OBIS Object identification system

COSEM Interface classes

AEnergy type

BChannel

CQuantity

DProcessing

EClassification

FHistorical

C la s s n a m e C a r d in a l i t y A t tr ib u te (s ) D a ta T y p e 1 . lo g ic a l_ n a m e (s ta t ic ) o c te t - s t r in g 2 . … .. ( . . ) … .. 3 . … … ( . . ) … .. S p e c i f ic M e th o d (s ) ( i f r e q u ir e d ) m /o 1 . … .. … .. 2 . … .. … ..

Mapping

DLMS/COSEM: Applications – Model - Protocol


Where we are

• 1997: DLMS UA established• 1999: First implementations hit the market• 2002:

– International standards published: IEC & CEN– Conformance testing in place– Training seminars launched

• 2003-2004: Global spread• 2005:

– DLMS UA membership reached 70– IEC standards revised, Internet profile added– Solidly established in electricity C&I segments– First gas implementations expected– Renewed interest for E-residential segment


DLMS/COSEM: Main concepts

• Common object model for all energy types

• Only few mandatory elements • Self-describing model and data

• Efficient data organisation• Negotiable contexts and capabilities

• Simple, media independent services• Efficient data access

• Efficient encoding


Common object model for all energy types

Class name

Logical name

Attribute 2

Attribute n

Method 1

Method n

Generic template

Register

logical_name

value

scaler_unit

reset

Interface classΣ Li A+ total

Value

Scaler_unit

Register 1

Meter volume

Value

scaler_unit

Register 2

Three phase import active energy

1.0.1.8.0.255

40153

kWh

Forward undisturbed meter volume

7.0.1.0.0.255,

7086

m3

• „Abstract” objects are the same for all energy types


1.0.1.8.0.255 12345 kWh

Only few mandatory elementsStandard object library

Clock

Profile

LDN

SAP

Register

Schedule

Assn. Mgmt. Logical device

LDN

Assn.

SAP RegisterRegister

Register

Comm.

•Simple building blocks to build simple or complex meters

•Mandatory objects: 2

• Logical Device Name

• Association

•Residential meters: few 10 objects

• Industrial meters: few 100 objects

RegisterRegister

Register

ClockSchedule

ProfileProfile

Logical device #2

Assn.

LDN


Self-describing model and data

Holds list oflogical devices

Identifies source of data

Holds list of objects & access rights Each attribute delivers

type and value

1.0.1.8.0.255 12345 kWh

Mgmt. Logical device

LDN

Assn.

Logical device #2

Assn.

SAP RegisterRegister

Register

RegisterRegister

Register

Clock Schedule

Comm.

ProfileProfileLDN

Holds configuration & identification data

Holds communication channel setup information


Logical device #2

Logical device #1

Efficient data organisation

Assn. #1

RegisterRegister ProfileLDN

Assn. #2

Register

Clock Schedule

Profile

• Any attributes can be captured in profiles:Read-out lists, Load profiles, Historical values…

• Like attributes can be captured in Register tables: Voltage dips, Harmonics…

n

…

......

...1

Name n...Name 1Entries

Captured elements (attributes)

Sort methodProfile name

Selective access

Logical name

Attribute 2

Attribute n

Method 1

Method n

Logical name

Attribute 2

Attribute n

Method 1

Method n


Negotiable contexts and capabilities

Physical layer

Intermediate layers

Application layer

Object model

ACSE xDLMS

Protocol stack

• xDLMS context

• list of services

• message length

• Application context

• referencing method

• authentication

• Layer parameters e.g.:

• PDU length

• Window size


Simple, media independent services

x = base_name

x + 8

x + n*8

x+ ...

x + offset

GET / SETattribute {class_id, logical_name, attribute_id}

ACTIONmethod {class_id, logical_name, method_id}

Read / Write{named variable}Mapping

Class_id, version

Attribute(s)

1. Logical name

2. Attribute 2

n. Attribute n

Specific method(s)

1. Method 1

n. Method n

• to turn the information into a series of bytes

• common for all objects


Efficient data access

Logical name

Attribute 2

Attribute n

Method 1

Method n

Logical name

Attribute 2

Attribute n

Method 1

Method n

Logical name

Attribute 2

Attribute n

Method 1

Method n

Logical name

Attribute 2

Attribute n

Method 1

Method n

• GET_WITH_DATABLOCK: delivers the information in bloc ks

• GET {attribute}: delivers the value of a single attribute

• GET-WITH-LIST {list of attributes}:delivers a list of attribute values

Objective: to minimise the number of exchanges and to match res ources

• GET {attribute_0}: delivers all attributes of an object


Effective encoding: A-XDR

For example: 20051021

32 30 30 35 31 30 32 21 6B 57 68ASCII

06 01 31 F4 4D 02 02 0F 03 16 30A-XDR

Value Scaler Unit

Type codes

k Wh


Residential meter data exchange - drivers

• Market liberalisation– All EU households eligible from 1st July 2007– Fragmented providers, volatile customer base

• EU Energy End Use Efficiency Directive– Provide customers with accurate and timely

information on consumption and prices to enable reaction on prices

• Renewable energy / Green certificates• Distributed / Embedded generation• Bi-directional energy flow


Know what you need

Device identification

Access control

Energy tariff registers

Voltage min/max

Load profile

Billing data

Load control

Readout lists

Comm. channels

Error objects

+ Association, 0.0.40.0.x.255

+ Register, 1.0.1.8.x.255

+ Register , 1.0.12.3/6.x.255

+ Profile generic , 0.0.21.0.x.255

+ Comm. channel setup objects

+ Clock, Schedule, Data

Profile generic, 1.x.99.1.0.255

Data, 0.0.42.0.0.255

Data, 0.x.97.97.0.255

Profile generic 0.x.98.1.0.255


ΣΣΣΣ Li Active power, C = 1

Measurement valuesElectricity, A = 1

Time integral 1, energy, D = 8

Data exchange control objectsAssociation objects, 0.0.40.0.x.255

Error object, 0.0.97.97.0.255

Number of power failures in all three phases, 0.0.9 6.7.0.255

Meter constants, 1.0.0.3.x.255Configuration program version number, 1.0.0.2.0.255Logical device name, 0.0.42.0.0.255

ΣΣΣΣ Li A+, energy, current value, 1.0.1.8.0.255

Channel, B = 0

Communication channel setup objects

Parameters

Model of a simple meter


Know what you have

1.0.1.8.0.255 12345 kWh

•Negotiate or pre-agree on lower layer parameters

•Negotiate or pre-agree on association and xDLMS context

•Retrieve object list or take it from the database


Example 1: Data link layer parameter negotiation

7EA0210002002321931964 818012050180060180070400000001080400000001 533B7E

7EA023210002002373F6C5 8180140502008006020080070400000001080400000001 CE6A7E

SNRM command frame sent with optional parameters:

Frame length: 33 bytes, parameters 21 bytes

UA response frame sent with parameters:

Frame length: 35 bytes, parameters 23 bytes

The parameters do not have to be sent, if default v alues are used


Example 2: Application Association establishment

7EA047000200230310413EE6E6006036A1090607608574050801018A0207808B0760857405080201AC0A80084142434445464748BE10040E01000000065F1F040000301DFFFF08237E

Application Association Request using low-level-sec urity: 71 bytes

Application Association Response using low-level-se curity: 83 bytes bytes

7EA0530300020023301329E6E7006142A109060760857405080101A203020100A305A10302010088020780890760857405080201AA0A80084142434445464748BE10040E0800065F1F040000301D190000071F0E7E

The AARQ/AARE exchange is not necessary, if pre-est ablished AAs are used


Example 3: Register object, scaler_unit

//Get attribute 2, value

C0018100030101480700FF0200 //13 bytes

//Response: data double long unsigned

C40181000600000905 // 9 bytes

//Get attribute 3, scaler_unit

C0018100030101480700FF0300

//data, structure of 2 elements

C401810002020FFF1623 // 11 bytes

The scaler_unit has to be read only once, or can be fixed in advance


Summary

• DLMS/COSEM allows to build simple or complex meters, using simple building blocks

• It provides a lot of flexibility, at a price of some overhead

• If certain choices are fixed, overheads decrease– this can be done in a companion standard

• DLMS/COSEM provides interoperability on the model level and on the protocol level


Thank you for your attention

dlms/cosem - how to make it simple - smart … kmethy.pdf · dlms/cosem - how to make it simple gy...

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