Pilz PSS SB FT, Basic license - Manual (Page 69)

Modular Block System: Burner Management 6-25
Timing diagrams
Setting the ENBL output automatically when the signal is recovered
Setting the ENBL output after a reset when the signal is recovered
A failure of S1 for a time less than the block set time means the
ENBL output does not switch to "0".
Only if
S1 drops out for a longer period of time will the ENBL output
reset.
The ENBL output is set immediately without the
need for intervention.
A failure of S1 for a length of time less than the block set time
means the ENBL output does not switch to "0".
Only if S1 fails for a longer period of time will the ENBL output
reset.
With signal recovery the ENBL output
is set only after a reset signal.