Pilz PSS SB FT, Basic license - Manual (Page 150)

6-106 Modular Block System: Burner Management
Standard Function Blocks
Failure of SyOK in all NEXT steps
ENBL is always reset if SyOK fails.
ENBL is set together with SyOK. If a NEXT bit exists at the time of setting
the
SyOK signal, the corresponding output bit sample is set.
Static NEXT signals are avoided in the complete program.
These NEXT bits are set exclusively as pulses.
SB159