Specific implementation of DLMS

Details of this implementation of the DLMS protocol are outlined below.

Physical layer

DLMS is available on the following communications ports, depending on your meter and options.

Meter Optical RS-232/RS-485 Modem Ethernet
ION9000   x   x
ION8650 x x x x
ION7400 x x   x
ION8800 x x x x

Data link layer

The following operation selections for HDLC (ISO/IEC 13239) are used in this implementation of DLMS:

  • unbalanced connection-mode data link operation

  • two-way alternate data transfer

  • the selected HDLC class of procedure is UNC, extended with UI frames

  • non-basic frame format transparency (HDLC Frame format type 3)

DLMS/COSEM specification Supported implementation

Maximum Info Field Transmit


Maximum Info Field Receive


Maximum Window Size Transmit


Maximum Window Size Receive


Transparent transfer of long MSDUs

Not supported

Inactivity timeout

120 seconds

Inter-frame time out

Determined by the value of the meter’s RxTimeout setting (configurable)

Device Addressing Length

4 bytes

Physical Device Address

The value of the meter’s Unit ID on the serial port being used for DLMS communications (configurable)

Logical Device(s)

Management Logical Device only at specified address 0x0001

Application layer

DLMS/COSEM specification Supported implementation

Supported application context

LN (logical name) referencing

Available services




set (supported for time synchronization only)


COSEM layer

Standard COSEM objects

Supported COSEM Objects

Association LN - 0-0:40.0.0*255

SAP Assignment - 0-0:41.0.0*255

Logical Device Name - 0-0:42.0.0*255

Clock - 0-0:1.0.0*255

Default COSEM objects

ION9000, ION8650, ION7400 and ION8800 meters have default COSEM objects configured to provide load profile and billing information.

You can also configure your meter to provide any data recorded by your meter’s data recorders; see “Changing the data exported to DLMS client software”.

NOTE: The register attributes listed in the table below are scaled by 1000 to provide resolution to three decimal points.
Supported COSEM Objects Capture Objects COSEM/OBIS representation of capture objects

Profile Generic 1-0:99.1.0*255 

(Load Profile)

Record Timestamp

Clock attribute 2 - 0-0:1.0.0*255

Status (see below)

Data attribute 2 - 0-0:97.97.0*255

kWh del int

Register attribute 2 - 1-1:1.29.0*255

kVARh del int

Register attribute 2 - 1-1:3.29.0*255

kWh rec int

Register attribute 2 - 1-1:2.29.0*255

kVARh rec int

Register attribute 2 - 1-1:4.29.0*255

Profile Generic 1-0:98.1.0*255

(Billing Data)

Record Timestamp

Clock attribute 2 - 0-0:1.0.0*255

Status (see below)

Data attribute 2 - 0-0:97.97.0*255

kWh del

Register attribute 2 - 1-1:1.8.0*255

kWh rec

Register attribute 2 - 1-1:2.8.0*255

kWh del-rec

Register attribute 2 - 1-1:16.8.0*255

kVARh del

Register attribute 2 - 1-1:3.8.0*255

kVARh rec

Register attribute 2 - 1-1:4.8.0*255

kVARh del-rec

Register attribute 2 - 1-1:128.8.0*255

kVAh del+rec

Register attribute 2 - 1-1:9.8.0*255

kW sd del-rec

Register attribute 2 - 1-1:16.4.0*255

kVAR sd del-rec

Register attribute 2 - 1-1:128.4.0*255

kVA sd del+rec

Register attribute 2 - 1-1:9.4.0*255

PF sign mean

Register attribute 2 - 1-1:13.0.0*255

Status capture object bitmap

When all bits are set, the status is considered invalid.

Status (unsigned 16 bit) Value

bit 15


bit 14


bit 13


bit 12


bit 11


bit 10


bit 9

DST Ended

bit 8

DST Started

bit 7

Power Down

bit 6

Power Up

bit 5

Time Changed

bit 4


bit 3

Master Reset

bit 2


bit 1


bit 0


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