Pilz PSS SB FT, Basic license - Manual (Page 125)

Modular Block System: Burner Management 6-81
Counting ignition attempts where time is exceeded
Setting input parameters
•
ITRY = 3: three ignition attempts
• T_V = 10s: time monitoring
Successful ignition after first attempt failed
The monitoring time, within which the next ignition
attempt is permitted, will be started if
SyOK is no
longer present and at the same time FLAs = 0, i.e.
no flame is established.
The acknowledgement (reset) and the new start-
command must be carried out before the
monitoring time cycle.
If the monitoring time T_V has
elapsed, a third RDY pulse is not
created.
The sequence must be started
from the beginning with the
initial step (reset+ start).
2nd ignition attempt
No 3rd attempt
because
T_V was
exceeded
When BIT0 =1, it signals to the SB157 that the ignition
transformer was activated.
If a “1” signal is still present at the FLAs input by the 0-
1 signal change from
BIT3, it means that ignition was
successful and no more RDY pulses will be created.
SB149 sequence continues.
1st ignition failure
(FLAs = 0)