Pilz PSS SB FT, Basic license - Manual (Page 56)

6-12 Modular Block System: Burner Management
Standard Function Blocks SB149
Setting/resetting the step without time delay but with monitoring time
Spurious signals:
The step enabling condition needs to be
present once only at the
COND input to set the
NEXT output.
The monitoring time W_V is started if all the step enabling conditions are met.
If the NEXT-output is not reset before the monitoring time cycle, the W_E output is
set. This means that the step enabling condition from the following step was not
met within the permitted time.
If the step enabling condition is met later during the next step, the NEXT, W_E
and D_E output are reset simultaneously.
The W_E output can be processed further according to user requirements.
Monitoring time
Multiple-recurring step enabling conditions have no negati-
ve influence on the function.
The monitoring time
W_V is started once only with the
initial 0-1 edge at the COND input.
In each case: a “1”-Signal at the
STEP input resets the outputs
NEXT, W_E and D_E.