Pilz PSS SB FT, Basic license - Manual (Page 48)

6-4 Modular Block System: Burner Management
Standard Function Blocks SB149
Programming guidelines
• STEP
The operand for the input parameter
STEP of SB149 must also be
assigned to the output parameter STEP from SB152 and also to the
input parameter STEP of SB157, if SB157 is used. This will enable the
individual steps of the sequence to reset during burner start-up.
The operand for the parameter STEP has the value 1 for the duration of
a cycle when a positive edge of the ENBL of SB152 is detected.
If several burners are operated with one PSS, each burner must be
assigned its own STEP operand. This enables the burners to be
controlled and monitored independently.
Example:
SB149
STEP
X - RDY
X - COND
M 70.00 .Burner 1 - X - STEP
B - W_BA
W - W_V
Z - W_T
B - D_BA
W - D_V
Z - D_T
NEXT - X
W_E - X
D_E - X
SB157
IGNI_TRY
B - SSNR
X - SyOK
X - BIT0
X - BIT3
X - FLAs
B - ITRY
M 70.00 .Burner 1 - X - STEP
W - T_V
Z - T
RDY - X