Profibus DP Mk2 Option Card Installation Manual
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Publication PUB088-005-00_1017
4.2 Segmented Single Highway System
The data highway may be connected as several segments coupled by repeaters. The repeaters or
actuator slaves will require termination components if they are on the end of the segment.
Alternatively, separately powered active termination devices can be used so that when the actuator is
switched off the bus performance is not affected.
Maximum number of devices participating
in the exchange of data
127 (addresses from 0 to 126, 0 is usually the PLC)
Maximum number of devices per segment
including repeaters
32
Maximum number of segments in series
EN50170 specifies a maximum of 4 repeaters between
any two devices. Some manufacturers of repeaters
allow more than this number.
Fig 13: Profibus Single Channel Data Highway Topology
Terminator
Bus Master
Segment 2
Segment 1
Segment 3
Repeater
Repeater
Powered
Active
Terminator