DLMS COSEM plugin for Data Loggers

Latest version: 5.0.2 build 1002. November 28, 2025.

The DLMS/COSEM plugin reads meter values from devices that follow IEC 62056 (also known as EN13757). It implements core parts of the DLMS/COSEM protocol to fetch current values, object lists, and time stamps. The plugin works with serial (RS232/RS485/optical) and TCP/IP interfaces. It supports password-protected meters and multiple concurrent device sessions. Use it when you need reliable, scheduled data collection from electricity, water, or gas meters.

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How it works

The plugin uses the object model defined by COSEM and the naming provided by OBIS. It supports two connection approaches: direct DLMS and DLMS initiated with the IEC 62021 optical handshake (this can change baud rate if the meter requests it). You configure an item (a request) that lists one or more physical device addresses, a logical device address, referencing method (logical name or short name), authentication level, and a list of response items (OBIS codes) to read. The plugin polls on a set interval, applies optional scaling, and exposes parser variables for export.

Examples of use

Data logger products consume parser variables exposed by this plugin. Below is an example showing a typical incoming DLMS value and the exported CSV line. The parser variable uses DATE_TIME_STAMP for storing a time stamp.

Example incoming (raw) from a meter via Advanced Serial Data Logger:

Connection: COM3, 9600, IEC handshake
Read request → OBIS 1.0.1.8.0.255 (active energy), OBIS 0.0.1.0.0.255 (clock)
Device replies → value: 12345.0 Wh, clock: 2025-11-28 08:00:00

Exported CSV (configured CSV export in Advanced Serial Data Logger):

"DATE_TIME_STAMP","device_id","active_energy_Wh","meter_clock"
"2025-11-28 08:00:00","meter_1","12345","2025-11-28 08:00:00"

Key features

Reads DLMS/COSEM devices over serial and TCP/IP connections.
Supports IEC 62021 handshake and baud rate change.
Handles password-protected meters and multiple logical devices.
Retrieves object lists and builds request templates.
Polls multiple devices and applies scaling to values.
Exposes parser variables for data exporting via export plugins.

Summary

The plugin provides a practical, standards-based way to read DLMS/COSEM meters over serial and network links. It supports object list retrieval, authentication, multi-device polling, and direct export integration with our data logger software.

Download | PDF manual