Siemens SINAMICS S120 Function Manual page 177

Figure 8-2
TM54F: interconnecting F-DI with plus-plus switching output on safety switching device
Figure 8-3
Dimensioning the load resistors - example 1:
According to the manufacturer's documentation, the leakage current of an F-DO of a safety
PLC for the P and F channels is 1 mA; in other words, it is around 0.5 mA higher than is
permissible for the F-DI.
The necessary load resistance is therefore R = 5 V/0.5 mA = 10 kΩ.
At the maximum supply voltage, the power loss for this resistor is:
P = (28.8 V)²/R = 83 mW. The resistor is to be permanently dimensioned for this power loss.
Safety Integrated
Function Manual, (FHS), 11/2009, 6SL3097-4AR00-0BP0
8.1 Input/output interconnections of a safety switching device with TM54F
TM54F F-DI at plus-minus switching safe output on safety switching device
(e.g. safety PLC)
TM54F F-DI at plus-plus-switching safe output on a safety switching device
(e.g. safety PLC).
Application examples
177