Siemens SIMATIC Power Line Booster Operating Instructions Manual page 41

PLB connection cable with individual length
If connection cables with individual length (Page 33) are used, this also results in smaller
configuration limits. It does not matter in this case whether the cable is shorter or longer than
8 meters. The maximum possible cable length is 30 meters in this case. Cables with
individual lengths are required, for example, when the distance between master and rail is
too large or a lifter is to be supplied via PLB.
Each cable with individual length reduces the number of slaves per segment by 10% of the
maximum configuration. If two cables with individual length are used, for example, in a
segment of a PDS application with connection cables that are generally ≤ 1 meter, the
configuration limit is reduced to
40 PLB – (2 • 10 %) = 32 PLB, which corresponds to a maximum number of 16 vehicles.
If connection cables ≥ 30 meters are required, 25% of the maximum configuration must be
subtracted per cable. These cable lengths must then also be added to calculate the
maximum segment length.
See also
PLB connection cable (Page 32)
Interruptions of the communication rail (switches/lifters/broken loops)
Each interruption of the integrated communication rail also results in increased attenuation of
the high-frequency powerline signal. When using switches or lifters in a segment, the
communication rail must be separated and the powerline signal must be transmitted to a
different rail section via cables. Note that these cables must always be shielded. We
recommend using PLB standard cables (Page 33).
As soon as a communication segment consists of multiple rail sections connected via cables
instead of an integrated rail, the total of all rail sections of the segment must be calculated.
For each rail section, you must subtract 7% from the maximum configuration for the
maximum number of slaves. If a switch is located in a communication segment of a PSS
application, for example, the powerline segment consists of 5 rail sections in total (1 rail
before the switch, 2 rail sections after the switch, and the two short movable rail sections on
the switch). This means the number of slaves must be reduced by 5 • 7% = 35% of the
maximum configuration, which means 26 slaves are still possible per segment.
The connection cables between the segments must be ≤ 8 meters in this case. If this is not
possible, an additional 10% reduction must be subtracted for the connection cable with
individual length. This can be the case, for example, when an inlet lifter with communication
is required at the segment start and this lifter is connected, for example, with a 15 meter
connection cable. The maximum number of stations is thus reduced by (2 • 7%) + 10% =
24%.
For more details on switches, lifters or broken loops and their cabling, see the sections
"Switches (Page 57)", "Loops (Page 55)" and "Rail interruptions (lifters) (Page 55)".
Power Line Booster
Operating Instructions, 11/2019, A5E36203125A-AG
Plant planning
3.4 System limits
41