User Manual

Control concept
Local control design
5
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Local interlocks
A command to ramp-up the plant [OpMod] =On, the damper output changes to
[TraSta] = Yes, indicating that a transient state is now active, in other words,
the damper is moving. This information is formed on the one hand from the
parameterized damper run time [TbTiDly] and, on the other hand, from the
feedback contact for the damper's mechanical stop.
The valve is blocked via input [EnSfty] as long as the damper is either blocked
or moving, in other words, an intervention via the operator unit directly on the
fan is prevented. When the transient state ends and the damper is open, the
Enable [EnSfty] is cancelled and the fan switched on via the program value
[ValPgm]. Enable of the program value [EnPgm] is a constant in this example.
Interlock among aggregates
The targeted interlocking is employed in a modified form from the superposed
plant control. To allow, , plant control to access the fan during smoke extraction
control, the interlock is not implemented by enabling the safety value [EnSfty],
but rather by enabling the critical value [EnCrit].
The fan is set to Off by the damper via Enable [EnCrit] until the damper is fully
open. The fan can only then start. The damper is held open via [EnCrit] as long
as the fan is running to prevent a mistaken operation that could destroy the
plant.
En
Val En Val
Val
Val
En En
P15 Pgm P4 Crit
PrV
a
l
Dstb PfmActv CritActv SftyActv TraSta
Y
e
s
O
p
M
o
d
[
O
n
/
O
f
f
]
Yes
OpMod
[On/Off]
Off
E,H
E,H
PrVal Dstb PfmActv CritActv SftyActv TraSta
P15 Pgm
P4 Crit
En
Val En
Val
Val
Val
En En
Damper
Cp:BO
Fan
Cp:BO