Fail-Safe Digital Input - Siemens SINAMICS G120 Operating Instructions Manual

4.5.7

Fail-safe digital input

To enable a safety function via the terminal strip of the inverter, you need a fail-safe digital
input.
Which devices are you allowed to connect?
The fail-safe digital input is designed for the following devices:
● Connection of safety sensors, e.g. emergency stop command devices or light curtains.
● Connection of pre-processing devices, e.g. fail-safe control systems and safety relays.
Signal state
The inverter expects signals with the same state at its fail-safe digital input:
● High signal: The safety function is deselected.
● Low signal: The safety function is selected.
Connecting P/P and P/M-switching fail-safe digital outputs
It is permissible to connect PP and PM-switching safe outputs to a fail-safe digital input.
Fault detection
The inverter compares the two signals of the fail-safe digital input. The inverter thus detects,
for example the following faults:
● Cable break
● Defective sensor
The inverter cannot detect the following faults:
● Cross-circuit of the two cables
● Short-circuit between signal cable and 24 V power supply
Converter with the CU250S-2 Control Units
Operating Instructions, 04/2018, FW V4.7 SP10, A5E31759476B AG
PP-switching digital output
Connecting a fail-safe digital input (Page 511)
4.5 Connecting the interfaces for the inverter control
For specific default settings of the terminal strip, e.g. default
setting 2, the inverter combines two digital inputs to form one
fail-safe digital input FDI 0.
PM-switching digital output
Installing
109