Pilz PSS SB FT, Basic license - Manual (Page 121)

Modular Block System: Burner Management 6-77
• Procedure after a failed attempt
The existing error message (e.g. flame monitor sequence interrupted)
must be reset, followed by pressing the start button. The plant enable is
set. If a re-ignition is permitted, the
RDY-output from SB157 is set for
one cycle. If you evaluate this signal you can start the sequence with the
initial ignition step, otherwise the sequence is started from new, and pre-
purging will take place.
• To call up SB157:
As SB157 determines with which step the sequence is started, then it
must be called up in the cycle before all the SB149 sequence blocks.
Example:
L M70.00 .Start ignition step
S M80.00 .NEXT ignition position
Initial step in the plant sequence
SB157
IGNI_TRY
B - SSNR
M 90.00 .ENBL - X - SyOK
M 84.00 .Ignition trans - X - BIT0
M 84.03 .Flame - X - BIT3
M 74.00 .Flame monitors - X - FLAs
B - ITRY
M 75.00 .Burner_1 - X - STEP
W - T_V
Z - T
RDY - X - M 70.00 .Start ign. step
SB149
STEP
X - RDY
X - COND
M 75.00 .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