MADDALENA microCLIMA U - 9.3 M-Bus Interface Information; 9.3.1 M-Bus Norms and Standards; 9.3.2 M-Bus Technical Specifications; 9.3.3 M-Bus Technical Data

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9.3 General information about the M-Bus interface
It is important to note that the acknowledged state of the art technology rules and the relevant legal restraints
(international and local; see 9.3.1 “Relevant Norms, Standards an Literature on the M-Bus”) are to be observed.
The installation has to be performed by authorized, skilled persons.
If the regulations and the information in the installation and operating instruction manuals are not strictly followed,
or if the installation is shown to be faulty, any resulting expenses will be charged to the company responsible for
the installation.
Recommended type of cable: Telephone cable J-Y(ST)Y 2x2x0.8mm².
It is important to make sure that the topology of the M-Bus network (cable lengths and cross-sections) is suitable
for the baud rate (2400 Bd) of the end instruments.
Further information can be found in the detailed ‘Application Note M-Bus’.
9.3.1 Relevant norms, standards and literature on the M-Bus
IEC 60364-4-41 (2005-12)
Low-voltage electrical installations - Part 4-41: Protection for safety -
Protection against electric shock
IEC 60364-4-44 (2007-08)
Low-voltage electrical installations - Part 4-44: Protection for safety -
Protection against voltage disturbances and electromagnetic disturbances
IEC 60364-5-51 (2005-04)
Electrical installations of buildings - Part 5-51: Selection and erection of
electrical equipment - Common rules
IEC 60364-5-54 (2011-03)
Low-voltage electrical installations - Part 5-54: Selection and erection of
electrical equipment - Earthing arrangements and protective conductors
EN 50310 (2010)
Application of equipotential bonding and earthing in buildings with
information technology equipment
EN 13757-1:2002, 2:2004, 3:2004
Communication systems for meters and remote reading of meters
The M-Bus
A Documentation, Version 4.8, M-Bus User group
TI Technical Journal
Texas Instruments Technical Journal Vol. 8, 1991 M-Bus
9.3.2 Additional technical specifications
The installation has to fulfil the requirements of the relevant norms, standards and literature (see paragraph 9.3.1)
and the specifications as follows.
Maximum voltage M-Bus
42 V
Minimum voltage M-Bus
21 V
Maximum ripple voltage
200 mV; EN 13757-2:2004; 4.3.3.6
Maximum voltage potential
differences
2 V
9.3.3 Technical data M-Bus
Primary address
0 (factory setting); 1 – 250 (configurable)
Baud rate
2400; 300 (configurable)
Connecting cable length
1 m
9.3.4 Number of possible read-outs
The number of possible read-outs depends on the number of instruments in the M-Bus network.
Number of instruments in
network
Read-outs per day primary
address
Read-outs per day secondary
address (without using SND NKE)
3
655
275
20
485
170
60
300
90
120
190
52
250
105
27
If fewer read-outs are carried out, the unused “credit” is stored in the instrument and can be used later.