Siemens SIMATIC S7 F Manual page 274

Fail-Safe Blocks
I/Os
Inputs:
Output:
Error Handling
None
8-86
Name Data Type
IN1 F_BOOL
IN2 F_BOOL
IN3 F_BOOL
IN4 F_BOOL
OUT F_BOOL
OUTN F_BOOL
Explanation Default
Input 1 1
Input 2 1
Input 3 1
Input 4 1
Output 1
Negating output 0
Fail-Safe Systems
A5E00085588-03