Siemens SINAMICS S150 - Page 243

Application examples
9.1 Input/output interconnections for a safety switching device with TM54F
Safety Integrated
Function Manual, 05/2010, A5E03264275A
243
6DIHW\UHOHYDQW
RXWSXW
0
0
([W9
70)
',
',
',
/RDGUHVLVWRUVLIUHTXLUHG


'
'
/
Figure 9-2 TM54F F-DI at plus-minus switching safe output on safety switching device (e.g. safety
PLC)
TM54F: interconnecting F-DI with plus-plus switching output on safety switching device


/RDGUHVLVWRUVLIUHTXLUHG
6DIHW\UHOHYDQW
RXWSXW
0
0
([W9
70)
',
',
',
'
'
Figure 9-3 TM54F F-DI at plus-plus-switching safe output on a safety switching device (e.g. safety
PLC).
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.