Connecting
3.7 Connecting PROFIBUS/MPI
SIMOTION D4x5-2
Commissioning and Hardware Installation Manual, 02/2012
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3.7 Connecting PROFIBUS/MPI
3.7.1 PROFIBUS connection components
Connection components
Individual nodes are connected by means of bus connectors and PROFIBUS cable.
Remember to provide a bus connector with a programming port at the ends of the subnet.
This will give you the option of expanding the subnet if required (for example, for a
programming device or SIMATIC HMI device).
Use RS 485 repeaters for the connection between segments and to extend the cable.
Segments
A segment is a bus cable between two terminating resistors. A segment can contain up to 32
nodes. In addition, a segment is limited by the permissible cable length, which varies
according to the transmission rate.
Terminating resistor
A cable must be terminated with its own surge impedance to prevent line disturbances
caused by reflections. Activate the terminating resistor at the first and last node of a subnet
or segment.
Make sure that the nodes to which the terminating resistor is connected are always supplied
with voltage during power-up and operation.