Alpha 6000S series User Manual page 142

P7.22 Dormancy threshold
Explanation:

If the residual between feed and feedback value is smaller than residual margin, PID regulation will stop and
the PID output maintain constant. As shown in Figure. 5-7-1.
 Setting this parameter correctly is helpful to balance the system output accuracy and stability. The residual
margin reduces the regulation accuracy of the system, but improves the system stability, to avoid unnecessary
fluctuations of output.

In the case of analog PID, the error margin sets P7.22 as the absolute value of physical quantity, which should
match with the range. In the case of PID, the error margin sets P7.22 as the rotating speed. It is showed in
Figure 5-7-1:
Reference
P7.23 PID Adjustment Characteristic
0: Positive Action
Explanation:
 Positive: When the PID output increases, the output frequency will increase and the controlled physical value
will increase, such as waterworks.
 Negative: When the PID output increases, the output frequency will increase, but the controlled physical
value will decrease, such as refrigeration system.
P7.24 Integral Adjustment Selection
0: When the frequency reaches the upper or lower limit, the integral adjustment will be stopped.
1: When the frequency reaches the upper or lower limit, the integral adjustment will be continued.
 Tips:
0 is suggested for the system requiring the rapid response. When the frequency reaches the upper or lower limit, the
integral adjustment will be stopped.
P7.25 Sleep Initiation
0: Non-initiation
 Tips:
In the case of rotating speed PID, there is not the function of sleep.
141
Feedback
Opereation Freq.
Figure. 5-7-1 Residual margin diagram
Chapter 5 Detailed Function Introductions
Setting range: 0.0~999.9 [0.0]
Setting range: 0.1 [0]
1: Negative Action
Setting range: 0.1 [0]
Setting range: 0.1 [0]
1: Initiation
Residual margin
Time
Time