Omron SYSDRIVE 3G3FV User Manual page 229

Advanced Operation
Adjusting PID Control
Step Response
This section explains how to adjust PID control parameters while observing the step response of the
control object.
1. Measuring the Step Response Waveform
Use the following procedure to measure the step response waveform.
a) Connect a load under the same conditions as for normal operation.
b) Set parameter b5-01 to "0" (PID control disabled).
c) Set the Inverter's acceleration time as low as possible, and input the step frequency reference.
d) Measure the response waveform of the feedback (i.e., the detection value).
Note Conduct the measurement so as to know the timing with the step input.
2. Calculating the PID Parameters
Draw a tangential line at the steepest point of the gradient of the step response waveform mea-
sured in procedure 1.
Measuring R
Measure the inclination of the tangential line, with the target value as "1."
Measuring L
Measure the time (unit: seconds) until the tangential line from the beginning of the step input joins
the time axis.
Measuring T
Measure the time (unit: seconds) from the point where the tangential line joins the time axis to the
point where it meets the target value.
Response
Target value
Chapter 6
Time
6-55