Lenze E94AYCEC - Manual (Page 25)

Lenze · E94AYCEC Communication module (POWERLINK CN) · Communication Manual · DMS 3.0 EN · 08/2014 · TD17
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5 Installation
5.2 Electrical installation
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5.2.2 Network topology
[5-4] Network topology for POWERLINK
Inside the segment only Ethernet hubs may be used as infrastructure elements. The hubs must
meet the requirements on class II repeaters acc. to IEEE 802.3u.
For this purpose Lenze offers the dual hub integrated into the communication module and the
separate eight-fold hub, type E94AZCEH.
Class I hubs and switches are not permissible since they have considerably longer delay times for the
frame forwarding and a bigger jitter. Both sizes reduce the real-time capability and dynamics.
The cable length between two POWERLINK nodes is limited to 100 m.
The topology rules (IEEE 802.3u) required for controlling the collisions may be violated in the
POWERLINK network segment since according to the POWERLINK access order, telegram collisions
are prevented. This enables a structure of lines and any hybrid forms between star and line
topology.
E94YCEP012

Note!
The use of class I hubs and switches inside the POWERLINK network segment is not
permitted.