Siemens SINAMICS RAILCTRL Function Manual page 41

CU transition
Multi-carrier systems can be scaled as required. To do this, the controlled variables are copied
over CU boundaries using DRIVE-CLiQ-based communication. The following conditions also
apply to the CU transition:
● A point-to-point connection via DRIVE-CLiQ must be established across the various CUs to
the drive objects.
● A maximum of 2 DRIVE-CLiQ connections (to the predecessor CU and to the successor
CU) are permitted for each Control Unit. Whereby, communication is possible only between
adjacent Control Units.
● The transfer must be synchronized by the higher-level control system (e.g. isochronous
PROFIBUS or PROFINET with IRT for SIMOTION).
Note
Use only DRIVE-CLiQ cables that do not contain any 24 V conductors for DRIVE-CLiQ
connections > 100 m or isolated 24 V power supplies of the Control Units. This prevents
equalizing currents flowing through DRIVE-CLiQ cables.
During the communication, the data required for the closed-loop control or open-loop control is
transferred to the predecessor or successor Control Unit. The RAILCTRL Technology
Extension uses the dual port RAM as send and receive buffer; this allows any number of axes
to be included in the complete group.
Note
If you use the RAILCTRL Technology Extension with SINAMICS Integrated (D4x5-2), then
communication across CUs is not possible!
The following diagram shows a typical interconnection of the drive objects (motor segments)
over several Control Units. This diagram is an extract from the topology (see "Figure 3-2
Topology for the multi-carrier system application example (Page 14)").
RAILCTRL
Function Manual, 09/2019, A5E38120767B
Function description
5.5 Communication
39