Pilz PSS SB FT, Basic license - Manual (Page 97)

Modular Block System: Burner Management 6-53
Reset spurious acknowledgements
Spurious acknowledgement as valve opens
After a fault lock-out due to an incorrect acknowledgement,
a reset can only occur (with a positive edge at
RSET), if the
valve is closed ( Pos1 =1).
The valve positions OPEN/CLOSE are polled to the feedback
inputs
Pos1 and Pos2.
The inputs are polled for validity and the control time
OPEN
→
CLOSE and CLOSE
→
OPEN is monitored. If
faults occur, the VAV output, together with the valve are
closed immediately and additionally ENBL = 0 is set.
If the “1”-Signal remains off for a time shorter than the
block's set time, the
ENBLoutput is not set to "0".
Only after a “1” signal is off for a longer period will the
ENBL output be reset.