Pilz PSS SB FT, Basic license - Manual (Page 93)

Modular Block System: Burner Management 6-49
• T: Timer which measures the time T_V
• RSET: Reset button (N/O)
Output parameters
• ENBL: Enable flag bit
ENBL = 1: this function is fault-free
(refer also to the Programming guidelines)
• VAV: Driving the valve
VAV = 0: bring the valve to its start position
VAV = 1: bring the valve to its operating position
Function
• Monitoring valve status (open/closed), the direction of a change in
position and the reaction time to a change in position
• Change in valve position after a request (start position, operating
position)
• The contact bounce time due to a change in position is one cycle.
Error messages
Any fault that is detected will be stored statically in the corresponding error
data word (SSNR) of DB015 (1st data block).
• Error messages in DB 015
- Bit 00: Status of the contact Pos1 does not correspond with the
previous drive direction.
Remedy: Check the contact and the switch time
T_V and reset
the error in the start position ( Pos1 operated, Pos2 not
operated, Dir2 = 0) .
- Bit 01: Status of the contact Pos2 does not correspond with the
previous drive direction.
Remedy: Check the contact and switch time
T_V and reset the
error in the start position ( Pos1 operated, Pos2 not operated
Dir2 = 0).
- Bit 02: Switch time for a change in position has been exceeded
Remedy: Check the switch time T_V for the contact(s) and the
reset the error in the start position ( Pos1 operated, Pos2 not
operated, Dir2 = 0).