Kamstrup M-Bus Master MultiPort 250D - Cabling and Network Conditions

17Kmstrup A/S • 5512853_C1_GB_01.2017
M-Bus Mster MultiPort 250D
The mster’s disply shows tht it is
configured s  repeter.
When the mster is configured s 
repeter, only the menu points which
cn be used with this configurtion
re displyed.
250D configured s repeter.
Min menu when 250D is configured s
repeter.
If the repeter is not connected to  mster or repeter vi terminls 53
nd 54, the symbol shown in the top right-hnd corner is displyed.
Note: The power supply MUST be switched off during reconfigurtion
between mster nd repeter.
4 Cbling
Typiclly unshielded twisted pir cble up to pprox. 1.5 mm
2
is used. The cbling topology is typiclly str or bus or 
combintion of both. The connection in M-Bus is independent of polrity nd no termintion resistnce t the end of
the cbling is needed.
If  cble type with shield is used, it is importnt tht the two M-Bus conductors re not connected to ground or shield.
No precise indiction s to mximum cble length in n M-Bus network cn be given s it depends on vrious
prmeters.
The two most importnt prmeters to consider when selecting cble for n M-Bus instlltion re cble resistnce
nd cble cpcity. Generlly speking, the resistnce limits the number of M-Bus slves, nd the cpcity limits the
communiction speed.
Furthermore, we recommend keeping  certin distnce between M-Bus cbles nd other cbles in order to minimize
noise from high-power electric mchinery.