Pilz PSS SB FT, Basic license - Manual (Page 105)

Modular Block System: Burner Management 6-61
• P+: Gas pressure monitor
P+ = 1: Gas pressure present
P+ = 0: No pressure or incorrect pressure
• P-: Air pressure monitor
P- = 1: Air pressure present
P- = 0: No pressure or incorrect pressure
• T_V: Monitoring time for checking the valves' seals (if valves are
seated)
In this time the monitoring process must be carried out at least
once, otherwise it will lead to a shutdown.
Permitted value range: - 32768 ... 32767
Time base: 10 s
T_V > 0: monitoring the seal check is carried out
T_V
≤
1: monitoring the seal check is not be carried out
(Note: time monitoring for calling up the checking process can
be used, for example, in plants with 72-hour operation).
• T: Timer which measures the time T_V
Output parameters
• ENBL: Enable flag bit
ENBL = 1: this function is error-free
(refer also to Programming Guidelines)
• RDY: Sequence output
If a block step is activated, the corresponding bit is set in the
output parameter
RDY.
• VAV1: VAV1 = 1: open safety valve
• VAV3: VAV3 = 1: open main valve
• VAV4: VAV4 = 1: open ventilation valve
• GP+: GP+ = 1: pressure monitor for P+ monitor (gas pressure)
• GP-: GP- = 1: pressure monitor for P- monitor (air pressure)
Function
Monitoring that the safety valve (VAV1), the main valve (VAV3) and the
ventilation valve (VAV4) are seated correctly.
See the diagram on the next
page.