ABB C1900RC, Руководство по эксплуатации

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22
PId
HYSt
At–HI
tErMS
P
At–LO
P
Start-up
PI
10.0
100
100
tYPE
A
A
b
Type B – Minimum Overshoot
SP
SP
X
x
4
Type A –
1
/
4
Wave Damping
…5 CONTROL OPERATION
…5.7.1 Auto-tuning Page
Hysteresis Value
The hysteresis value is entered in engineering units and is used to determine when to
change the controller output value.
'At Set Point' Tuning only
– when the process variable crosses the hysteresis band
(plus and minus the hysteresis value), the controller output changes by plus and
minus the
StEP
value from its initial starting value. The hysteresis value should be
set as small as possible but larger than the noise in the process variable signal, to
allow the best possible response data.
Set the hysteresis value required (in engineering units).
Auto-tune High Limit
The process variable must be between the high and low limits when auto-tuning is
activated. If the process value exceeds one of these, the auto-tuning cycle is shut off
automatically by reverting to the manual control mode and returning the controller
output to the value set when the auto-tuning was activated. The high and low values
are the limits for cancelling auto-tune execution.
Set the value required (in engineering units), the decimal point is set automatically.
Auto-tune Low Limit
Set the value required.
Three Term Control Parameters
Select the Proportional, Integral and Derivative terms required.
Control Type
Select:
‘
A ’ for quickest response with
1
⁄
4
wave damping.
or
‘
B ’ for quickest response with minimum overshoot.
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