Pilz PSS SB FT, Basic license - Manual (Page 136)

6-92 Modular Block System: Burner Management
Standard Function Blocks
The output FLAI is set after the ignition
safety time. If the flame monitoring
block has not detected a flame before
the ignition safety time, this is signalled
via
FLAI = 1, a flame monitor fault.
This fault creates a fault lock-out for the
burner cycle.
After the pilot flame has been
monitored and its presence detected, it
is offset for a set time, the ignition
transformer switched off and after that
the gas ignition valve is closed.
The times for these will be configured
by the user in the step blocks (SB 149)
of the sequence, in the same way as
the ignition safety time.
The RDY output (as
byte) indicates the
current status of
SB158.
The individual bits
from this byte must
be linked with the
corresponding step
block so that a timed
output cycle occurs.
The duration of the
individual
RDY bits
and as such the total
cycle will be
determined by the
NEXT input.
The individual steps
will be enabled with a
control byte on the
NEXT input.
During the whole
cycle
SyOK must
remain = 1.
The SyOK input
enables the ignition
cycle.
A 0 signal at this input
sets the outputs to a
safe state.
SB158