Omron MX2 Series User Manual page 358

7 Other Functions
PID Variable Range
This function limits the PID output to within the variable range defined based on the target value.
To use this function, set the PID Variable Range Limit (A078) as a percentage of the maximum fre-
quency. Then, the output frequency will be limited to within a range of Target value ± (A078).
This function is disabled when A078 is set to 0.0 or PID Selection (A071) is set to 02 (Enabled: Reverse
output enabled).
PID output [%]
PID target value
PID Reverse Output
Under normal PID control (A071 = 01), the frequency reference to the inverter will be limited to 0 Hz if
the result of PID operation is a negative value. However, when the PID Selection (A071) is set to 02
(Reverse output enabled), reverse output is enabled for the inverter if the result of PID operation is a
negative value.
When A071 is set to 02, the PID Variable Range Limit (A078) setting is disabled.
PID Gain Adjustment
If the PID function does not provide a stable response, adjust the appropriate gain setting according to
the table below.
Changes in target value are not reflected quickly on feedback value.
Changes are reflected quickly on feedback value, but not stable.
Target and feedback values do not match quickly.
Feedback value fluctuates unstably.
Increasing PID P Gain does not improve response speed.
Increasing PID P Gain results in fluctuating and unstable feedback value.
PID Deviation Excessive (OD)
You can set the PID Deviation Excessive Level (C044) for PID control. This inverter can be configured
to output this signal to a multi-function output terminal if the PID deviation ε reaches the level set in
C044 or higher. The inverter will not shut off its output (trip), however.
Allocate the Multi-function Output P1/P2 Selection (C021/C022) or the Multi-function Relay Output (MA,
MB) Function Selection (C026) to 04 (OD).
Set C044 in units of percentage as 100% of the 1st/2nd Maximum Frequency (A004/A204).
7 - 48
PID output range
Phenomenon
Multi-function Compact Inverter 3G3MX2-V1 User's Manual (I585-E1)
PID Variable Range Limit (A078)
PID Variable Range Limit (A078)
Time [s]
Adjustment
Increase PID P Gain (A072).
Decrease PID P Gain (A072).
Decrease PID I Gain (A073).
Increase PID I Gain (A073).
Increase PID D Gain (A074).
Decrease PID D Gain (A074).