MT880 is an industrial electricity meter from the Slovenian manufacturer Iskraemeco. The suffix "M" after the MT880 indicates the modular version, which includes a slot for a plug-in module, which adds additional communication interfaces to the electricity meter. It is characteristic of this electricity meter that it is currently (year 2017) the fastest on our market (from the point of view of computing power), contains the most usable communication interfaces (2x RS485, GSM/GPRS/UMTS), and is generally the most advanced.

D2000 V25 Documentation > Iskra MT880-M > IMG_20171222_110247.jpg

View of MT880-M with front cover and without front cover

In the picture without the front cover, the main interfaces of the electricity meter are marked:

1. Terminal box of the electrical network. In the picture, only the first phase and ground are connected.
2. Integrated RS485 serial bus interface.
3. RS485 interface on the plug-in module.
4. Connector for GSM network antenna.
5. Optical interface.

SEP2 MeterView 2017 utility software

The utility software SEP2 MeterView 2017 was supplied with the electricity meter. With it, it is possible to read the values of all available registers and also to change their values and thus configure the behavior of the electricity meter.

D2000 V25 Documentation > Iskra MT880-M > meterview.png

Sample from SEP2 MeterView 2017

Parameters for DLMS communication

The electricity meter via IP uses IEC62056-47 on the relational layer, via RS485 it uses HDCL. The following addresses are used:

HDLC physical address = the value 16 is added to the bottom two digits of the serial number. For example, the electricity meter in the picture has the serial number 069788138, the address is 38 + 16 = 54.
HDLC logical address = 1
HDLC client address = 16 (0x10) for unauthorized access without password, 1 (0x01) with password
password = 12345678

Other observations

When establishing a connection via HDLC, it is necessary that the SNRM frame does not contain values for maximumInformationFieldTransmit/Receive in its payload. For the fields maximumWindowSizeReceive/Transmit, the 4-byte value 1 worked ok. If the SNRM payload contains the values maximumInformationFieldTransmit/Receive, the meter ignores the request - it does not send any (positive or negative) response.