Cabling - Kamstrup M-Bus Master MultiPort 250D Installation And User Manual

The master's display shows that it is
configured as a repeater.
When the master is configured as a
repeater, only the menu points which
can be used with this configuration
are displayed.
If the repeater is not connected to a master or repeater via terminals 53
and 54, the symbol shown in the top right-hand corner is displayed.
Note: The power supply MUST be switched off during reconfiguration
between master and repeater.

4 Cabling

Typically unshielded twisted pair cable up to approx. 1.5 mm
combination of both. The connection in M-Bus is independent of polarity and no termination resistance at the end of
the cabling is needed.
If a cable type with shield is used, it is important that the two M-Bus conductors are not connected to ground or shield.
No precise indication as to maximum cable length in an M-Bus network can be given as it depends on various
parameters.
The two most important parameters to consider when selecting cable for an M-Bus installation are cable resistance
and cable capacity. Generally speaking, the resistance limits the number of M-Bus slaves, and the capacity limits the
communication speed.
Furthermore, we recommend keeping a certain distance between M-Bus cables and other cables in order to minimize
noise from high-power electric machinery.
Kamstrup A/S • 5512853_C1_GB_01.2017
250D configured as repeater.
is used. The cabling topology is typically star or bus or a
2
M-Bus Master MultiPort 250D
Main menu when 250D is configured as
repeater.
17