Pilz PSS SB FT, Basic license - Manual (Page 95)

Modular Block System: Burner Management 6-51
Programming guidelines
• ENBL
The enable ENBL of SB154 must be supplied to the AND-operation
before the global input ERR or to the AND-operation before the global
input CHAI of SB152 “Burner: Start and operator elements”. The
decision to use ERR or CHAI depends on the user and the respective
standards regarding error reaction.
ERR: If an error is present, a controlled shutdown occurs when
AuSt = 1 with restart.
CHAI: If an error is present, a safety shutdown occurs.
A programming example can be found in Chapter 8 under “Managing
enables”.
• Dir1 and Dir2
Driving one flap: the drive must be driven in one direction only i.e. Dir1
and Dir2 must not be driven simultaneously.