Communication by M-BUS protocol

M-BUS (Meter-Bus) is a communication standard which is developed in the co-operation of University Padeborn and Texas Instruments German company.

M-BUS is determined for applications of the data collection from consumption meters of various types (for example, drinking and commercial water, gas, heat, electric energy).

With regard to relatively narrow and specialized application area, special requirements are required on M-BUS. It must ensure the connectivity of high number of devices (ordinarily a few sets) to the distance of a few kilometers. The data transfer must be resistant to errors on a high level. On the other hand, the typical feature of the application is reading the measured values not too often with low requirements to responses in the real time - communication rate is only from 300 to 9600 Bd.

Examples of concrete meters:

ULTRAHEAT from Landis company, F4 from SVM company, MULTICAL from Kamstrup company, INFOCAL from Danfoss company, Actaris (former Schlumberger), EESA, SuperCal, SonoGyr, Calmex, Schninzell, Glorices, Spanner-Polux etc.

M-BUS HW converter:

Meters communicate by the M-BUS protocol over the special physical interface (36V) and that's why the HW converter from M-BUS to RS232, RS485, RS422 or Ethernet is needed. For example, the following converters were tested:

- Converter DM-MB2ET (M-BUS/Ethernet) by the AMiT company ( Notes:
- The Ethernet parameters can be modified via the Web interface. The default values are: Network address=, TCP/UDP port number=2000, Ethernet transfer type=TCP
- It is necessary to set the "Direct" mode, i.e. the transparent character transfer between M-BUS and Ethernet without modification.
- SLC-31/32 converter (M-BUS/RS232) from the Elsaco Czech company ( Notes:
- Returns ECHO chars
- Max. number of slave modules: 3 (or 20 if there is an external power supply)
- Recommended setup in Serial link parameters: Baud rate=2400, Parity=EVEN, Filter ECHO chars=Yes
- AD-01 converter (M-BUS/RS232) of the Westermo company ( Notes:
- Max. number of slave modules: 120
- If meters with different data rate are used, then the converter can be set up for autobaud mode.
- The PiiGAB M-Bus 810 converter (M-BUS/Ethernet and M-BUS/RS232) by the Swedish PiiGAB company ( Notes:
- The standard Ethernet parameters are: TCP/UDP port number=10001, Ethernet transfer type=UDP.
- Has 4 ports for M-BUS
- Converter (M-BUS/RS232) by the Polish Control company ( Notes:
- Max. number of slave modules: 10, 60 or 400. The M-Bus Master 400 type is used for power supply and signal conversion in networks with more than 255 devices, or devices that extremely stress the network.
- All converters allow transfer speeds in the range from 300 to 19200 baud.
- There is no fault to use any other converter.

PROMOTIC communication driver PmMBus:

The most suitable solution for the M-BUS communication in the PROMOTIC application, is represented by using the PROMOTIC driver:

PmMBus - Driver for communication with M-BUS protocol

This driver is designed for communication via the computer's serial port or via Ethernet and configured on a very general level. It enables reading current values, history, maxima, etc. It is already configured for some types of concrete meters but it enables also to set up the message on a general level, namely both on the level of standard incomming messages and even on the byte level of the M-BUS protocol.
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