*
For additional assistance, please contact Toshiba Adjustable Speed Drive Marketing Dept. at (800) 872-
2192
54
Time
Improve by decreasing
Proportional Gain,
decreasing Integral Time
40
Hz
30
Time
40
Improve by increasing
Proportional Gain
Hz
30
Time
More PID parameters:
¾
Lag Time Constant (FEEDBACK PARAMETERS group) determines the drive reaction time.
Decrease
Lag Time Constant to improve drive reaction to process variable change.
Too long of a
lag time can result in under/overshoot.
¾
When PID is turned on, Lower Limit Frequency in FUNDAMENTAL PARAMETERS #1 group is not
effective. Adjust PID Lower Limit Frequency in the FEEDBACK PARAMETERS group as desired
for a unique PID lower limit.
¾
Use PID Deviation Upper Limit and PID Deviation Lower Limit (in FEEDBACK PARAMETERS
group) to limit the amplitude of the error signal. The values entered here are in percent of Maximum
Output Frequency (FUNDAMENTAL PARAMETERS #1 group). Use on systems that change quickly
and drastically. PIDDLL applies to the error when the feedback is less than the setpoint. PIDDUL
applies to the error when the feedback is greater than the setpoint
The G3’s ACC/DEC control occurs before the PID block; in the G2+, it acted on the PID output. The Lag
Time Constant and PID Deviation Upper/Lower Limits serve to smooth out the drive response.
The G3 does not give the user an indication that PID is on.
