Plant installation
4.11 Switches
Power Line Booster
Operating Instructions, 11/2019, A5E36203125A-AG
57
4.11
Switches
If possible, use switches only for separation of segments during plant planning (as segment
cut). If the switch must be used within a communication segment, this is possible with a
reduction of the number of devices in the segment according to the section Maximum
number of stations (Page 40).
4.11.1
Switch as segment cut
If you are using the switch for a segment change, the rails are replacing the separator on the
moving switch section. Because two powerline segments are separated from each other in
the process, you must ensure during cabling that there is no signal coupling between the
high-frequency signal and the neighboring segment.
If this rail section/separator is longer than 1 meter, we recommend installing an additional
short separator on the rail sections (see figure Segment cut (Page 54)) in front of and behind
the switch. This prevents the vehicle sliders from temporarily connecting a long and non-
terminated rail section with the communication segment when traveling over the cut. The
sudden impedance change caused by such a connection would result in communication
problems. The ends of the PL rails must be terminated with a PLB TC module as with each
segment start/segment end.
As described in section Rail grounding (PE rail) (Page 53), it is essential to ground the PE
rail at both ends with short cables against the steel structure. Also, it is necessary to ground
the PE cable of the supply cables EMC-compliant with short cables against the steel
structure. This can be, for example, at the location where the supply cables for the switch are
connected. If the switch connector is designed as a plug-in connector, the connector can
also be used for grounding the PE cable against the steel construction.
Summary of Contents for SIMATIC Power Line Booster
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