ABB ACH550-01 - Parameter Listing and Descriptions; What this chapter contains; Parameter groups

160 Serial communications
ACH550-01 User's Manual
PID control feedback source selection
Code Description Range
4010 SET POINT SEL 0…19
Defines the reference signal source for the PID controller.
• Parameter has no significance when the PID regulator is by-passed
(see 8121
REG BYPASS CTRL).
8 =
COMM – Fieldbus provides reference.
9 =
COMM+AI1 – Defines a fieldbus and analogue input 1 (AI1)
combination as the reference source. See Analogue input reference
correction on page 160.
10 =
COMM
*
AI1 – Defines a fieldbus and analogue input 1 (AI1)
combination as the reference source. See Analogue input reference
correction on page 160.
Analogue 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 = AI1 for values 14…17)
• B = Correcting reference
(= AI1 for values 9, 10 and = AI2 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.
4014 FBK SEL 1…13
Defines the PID controller feedback (actual 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.
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
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