ABB ACS550 Series, User Manual

Page: 163 / 310

ACS550 User’s Manual 163
Parameters
Analog input reference correction
Parameter values 9, 10 and 14…17 use the formula in the following table.
Where:
• C = Main reference value
( =
COMM
for values 9, 10 and
=
AI
1 for values 14…17)
• B = Correcting reference
( =
AI
1 for values 9, 10 and
=
AI
2 for values 14…17).
Example:
The figure shows the reference source curves for
value settings 9, 10 and 14…17, where:
• C = 25%.
• P 4012
SETPOINT MIN
= 0.
• P 4013
SETPOINT MAX
= 0.
• B varies along the horizontal axis.
4011 INTERNAL SETPNT
Sets a constant value used for the process reference.
• Units and scale are defined by parameters 4006 and 4007.
4012 SETPOINT MIN
Sets the minimum value for the reference signal source.
• See parameter 4010.
4013 SETPOINT MAX
Sets the maximum value for the reference signal source.
• See parameter 4010.
4014 FBK SEL
Defines the PID controller feedback (actual signal).
• You can define a combination of two actual values (
ACT
1 and
ACT
2) as the feedback signal.
• Use parameter 4016 to define the source for actual value 1 (
ACT
1).
• Use parameter 4017 to define the source for actual value 2 (
ACT
2).
1 =
ACT
1 – Actual value 1 (
ACT
1) provides the feedback signal.
2 =
ACT
1-
ACT
2 –
ACT
1 minus
ACT
2 provides the feedback signal.
3 =
ACT
1+
ACT
2 –
ACT
1 plus
ACT
2 provides the feedback signal.
4 =
ACT
1*
ACT
2 –
ACT
1 times
ACT
2 provides the feedback signal.
5 =
ACT
1/
ACT
2 –
ACT
1 divided by
ACT
2 provides the feedback signal.
6 =
MIN
(
ACT
1,2) – The smaller of
ACT
1 or
ACT
2 provides the feedback signal.
7 =
MAX
(
ACT
1,2) – The greater of
ACT
1 or
ACT
2 provides the feedback signal.
8 = sqrt(
ACT
1-2) – Square root of the value for
ACT
1 minus
ACT
2 provides the feedback signal.
9 = sq
A
1+sq
A
2 – Square root of
ACT
1 plus the square root of
ACT
2 provides the feedback signal.
10 = sqrt(
ACT
1) – Square root of
ACT
1 provides the feedback signal.
11 =
COMM FBK
1 – Signal 0158
PID COMM VALUE
1 provides the feedback signal.
12 =
COMM FBK
2 – Signal 0159
PID COMM VALUE
2 provides the feedback signal.
13 =
AVE
(
ACT
1,2) – The average of
ACT
1 and
ACT
2 provides the feedback signal.
4015 FBK MULTIPLIER
Defines an extra multiplier for the PID feedback value FBK defined by parameter 4014.
• Used mainly in applications where the flow is calculated from the pressure difference.
0.000 =
NOT SEL
– The parameter has no effect (1.000 used as the multiplier).
-32.768…32.767 – Multiplier applied to the signal defined by parameter 4014
FBK SEL
.
Example:
Code Description
Value setting Calculation of the AI reference
C + B C value + (B value - 50% of reference value)
C * B C value · (B value / 50% of reference value)
C - B (C value + 50% of reference value) - B value
C / B (C value · 50% of reference value) / B value
120
100
80
60
40
20
0
0
100%
9, 14 (+)
16 (-)
10, 15 (*)
17 (/)
B
FBK Multiplier A1 A2 –
×
=