Siemens SIMATIC S7 FH - Installation in Cyclic Interrupt Obs; Safety Program Can be Installed in ob 3 X ONLY

Fail-Safe Blocks
Fail-Safe Systems
8-8 A5E00085588-03
8.1.5 Installation in Cyclic Interrupt OBs
!
Safety Note – Safety Program can be installed in OB 3x ONLY
Fail-safe blocks can only be installed in a cyclic interrupt OB 3x. Installation in the
OB 1 is not permissible.
The cycle time of the cyclic interrupt OB is assigned parameters in HWCONFIG
(CPU parameters "Cyclic Interrupts, Execution". See "Monitoring the F Cycle
Time").