Siemens SINAMICS G120 Operating Instructions Manual page 117

Special measures to prevent cross-circuits and short-circuits
The routing of cables over longer distances, e.g. between remote control cabinets, increases
the risk of damaging cables. Damaged cables raise the risk of an undetected cross-circuit with
power-conducting cables laid in parallel. A cross-circuit can cause interruption to the transfer
of safety-related signals.
To reduce the risk of cable damage, you need to lay signal lines in steel pipes.
Special requirements placed on EMC-compliant installation
Use shielded signal cables. Connect the shield at both conductor ends.
In order to connect two or more inverter terminals, use the shortest possible jumpers directly
at the terminals themselves.
Bright and dark test
The inverter filters signal changes using bright and dark tests at the fail-safe digital input using
an adjustable software filter.
Converter with the CU240B-2 and CU240E-2 Control Units
Operating Instructions, 01/2017, FW V4.7 SP6, A5E34259001B AD
Installing
4.5 Installing Control Unit
117