Pilz PSS SB FT, Basic license - Manual (Page 63)

Modular Block System: Burner Management 6-19
Timing diagrams
Signal cycle with an uninterrupted burner start-up or uninterrupted burner stop sequence
Monitoring for “Flame not established”
A “1”-Signal at the MONI input and a “0”-Signal at the RUN input, F_S1 and
F_S2 are monitored for “0” and “1” respectively, i.e. for “flame not established”.
During the ignition process, the signals at
F_S1 and F_S2 must change, i.e.
SB 150 must change from detecting for “flame not established” to detecting
for “flame established”. During this switching time the
F_S1/F_S2-inputs
are not evaluated: they can have any status.
Monitoring for “flame established”
A “1”-Signal at the MONI input and a “1”-
Signal at the RUN-input means F_S1 is
monitored for “1” and F_S2 for “0”, i.e. for
”flame not established”.
If the MONI input is reset,
monitoring is deactivated and the
flame can be extinguished
without the block generating an
error message (
ENBL = 0).