ABB ACS550-02 User Manual page 126

124
Code Description
4003 DERIVATION TIME
Defines the PID Controller's derivation time.
• You can add the derivative of the error to the PID controller
output. The derivative is the error value's rate of change. For
example, if the process error value changes linearly, the
derivative is a constant added to the PID controller output.
• The error-derivative is filtered with a 1-pole filter. The time
constant of the filter is defined by parameter 4004
.
FILTER
0.0 = – Disables the error-derivative part of the PID
NOT SEL
controller output
0.1...10.0 = Derivation time (seconds)
4004 PID DERIV FILTER
Defines the filter time constant for the error-derivative part of the PID controller output.
• Before being added to the PID controller output, the error-derivative is filtered with a 1-pole filter.
• Increasing the filter time smooths the error-derivative, reducing noise.
0.0 = – Disables the error-derivative filter.
NOT SEL
0.1...10.0 = Filter time constant (seconds).
4005 ERROR VALUE INV
Selects either a normal or inverted relationship between the feedback signal and the drive speed.
0 = – Normal, a decrease in feedback signal increases drive speed. Error = Ref - Fbk
NO
1 = – Inverted, a decrease in feedback signal decreases drive speed. Error = Fbk - Ref
YES
4006 UNIT
Selects the unit for the PID controller actual values. (PID1 parameters 0128, 0130, and 0132).
• See parameter 3405 for list of available units.
4007 DSP FORMAT
Defines the decimal point location in PID controller actual values.
• Enter the decimal point location counting in from the right of the entry.
• See table for example using pi (3.14159).
4008 0 % VALUE
Defines (together with the next parameter) the scaling applied to
the PID controller's actual values (PID1 parameters 0128, 0130,
and 0132).
• Units and scale are defined by parameters 4006 and 4007.
4009 100 % VALUE
Defines (together with the previous parameter) the scaling applied
to the PID controller's actual values.
• Units and scale are defined by parameters 4006 and 4007.
Start-Up
Error
100%
PID DERIV
0%
PID output
Gain
P 401
Units (P4006)
Scale (P4007)
P 4009
P 4008
-1000%
Process Error Value
D-part of controller output
P 4003
4007 Value Entry Display
0 0003 3
1 0031 3.1
2 0314 3.14
3 3142 3.142
+1000%
0% 100%
Internal scale (%)
t
t