User Manual

Control concept
Local control design
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CM110664en_07 73 | 351
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