Omron MX2 Series User Manual page 356

7 Other Functions
PID Operation
(1) P Operation
In this operation, the control volume is proportional to the deviation (difference between the
target value and the current value).
Target value
Control volume
(2) I Operation
In this operation, the control volume is proportional to the time integral value of the deviation. The
P operation is less effective as the current value approaches the target value due to smaller devia-
tion, taking a long time to reach the target value. The I operation compensates this disadvantage.
Target value
Control volume
(3) D Operation
In this operation, the control volume is proportional to the percentage of change in the devi-
ation. Because using only the PI operation is time-consuming, the D operation is used to
effectively compensate for the disadvantage in responsiveness.
Target value
Control volume
PID Target Value Setting Unit and PID Scale
When the PID function is enabled, the setting unit for the following parameters is changed to percent-
age as 100% of the maximum frequency (d004 is always in units of %).
You can set the PID Scale (A075) to perform scale conversion of these parameters:
Value after conversion = Value before conversion
d004 F001
A023 A024
A031 A032
Precautions for Correct Use
When the following parameters are read or written via Modbus communication, the data unit
differs between read and write operations. Set parameter values in units of 0.01 Hz for writing
and in units of the following percentages (as 100% of the maximum frequency) for reading.
F001: 0.01%
A011, A012, A020/A220, A021 to A035, A101, A102, A145: 0.1%
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Step transition
Large
A072
Small
Step transition
Small
A073
Large
Step transition
Large
A074
Small
A011 A012
A025 A026
A033 A034
Multi-function Compact Inverter 3G3MX2-V1 User's Manual (I585-E1)
Ramp transition
Large
A072
Small
Ramp transition
Small
A073
Large
Ramp transition
Large
A074
Small
× PID Scale (A075)
A020 A220 A021
A027 A028 A029
A035 A101 A102
A022
A030
A145