ABB C505 User Manual page 39

2.14.2 Using the Control Efficiency Monitor
450. 2
500. 0
70
+
rAtE
10. 1
OVEr
10
rAtO
0. 2 5
Prd
35
SEtL
0. 3
IAE
2. 1
450. 2
500. 0
Press and hold the lower
Note.
If the front panel keys are not operated for 60 seconds whilst any
Control Efficiency Monitor frame is being displayed, the instrument
reverts to the first operating frame.
Rate of Approach to Set Point
The rate of change of the process variable between 5 and 95% of the
step change (Y ), measured in engineering units per minute.
2
Rate of approach =
Overshoot
The maximum error, expressed as a percentage of the set point.
Set Point
Overshoot =
Decay Ratio
The ratio of the amplitude of the first and second overshoots.
X
2
Ratio =
X
1
Period
The time (in seconds) between the first two peaks (t
Settling Time
The time taken (in minutes) for the process variable to settle within
±2% of the set point value (t
Error Integral
The integral of the error value until the process variable settles to
within ±2% of the set point value in 'engineering-unit hours'.
Error integral =
Return to the first operating frame.
2 OPERATOR LEVEL...
and
Y
1
t
approach
X
1
x100
).
settle
t
settle
| |
PV – SP dt
0
keys for 2 seconds.
).
period
35