YASKAWA GA700 Technical Manual page 621

The following diagram shows the operation principle when the feedback value has fallen too low, and the drive
detects feedback loss. The operation is the same when the drive detects excessive feedback.
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PID Sleep
PID sleep stops drive operation if the PID output or the frequency reference falls below b5-15 [PID Sleep
Function Start Level]. This function is used to shut off drive output when the motor has decelerated down to the
designated frequency.
The drive will automatically restart the motor once the PID output or the frequency reference rises above b5-15
for the time set in b5-16 [PID Sleep Delay Time].
The following time chart shows PID Sleep function.
Note:
• The PID Sleep function remains enabled even when PID control is disabled.
• The drive will stop the motor according to b1-03 [Stopping Method Selection] when the PID Sleep function is triggered.
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Fine-Tuning PID
Fine-tune the following parameter settings to have PID control eliminate problems with overshoot and oscillation.
• b5-02 [Proportional Gain Setting (P)]
• b5-03 [Integral Time Setting (I)]
• b5-05 [Derivative Time (D)]
• b5-08 [PID Primary Delay Time Constant]
YASKAWA ELECTRIC SIEP C710617 01B YASKAWA AC Drive GA700 Technical Manual
Figure 11.36 Time Chart for PID Feedback Loss Detection Time
Figure 11.37 PID Sleep Time Chart
11.3 b: Application
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