Pilz PSS SB FT, Basic license - Manual (Page 26)

4-2
Intended Use
Modular Block System: Burner Management
Intended use of the standard function blocks
SB149: Sequence control
SB149 is a standard function block designed to control operating cycles.
For this reason, several SB149 blocks can be arranged together to form a
sequence. Each SB149 in this sequence waits for the ready signal from the
previous step and for the step enabling conditions to be met, before it
becomes active.
A PSS can monitor and control several work cycles in which each cycle is
assigned a separate sequence.
NOTICE
During a sequence only one SB may be active. This requirement is only
met if output parameter
NEXT from the current step is connected to input
parameter RDY on the next step. Make sure the parameters are assigned
accordingly.
SB150: Flame monitoring
SB150 is a standard function block for monitoring flames from the moment
the burner starts until the moment the burner stops. The block checks
whether the flame is present or absent, depending on the operating status.
SB151: Transient suppression
SB151 is a standard function block for monitoring a N/C contact, e.g. on a
pressure monitor. The N/C contact must be wired with a test pulse.