User manual

Chapter 5 Parameter Introductions

deviations occur and the regulation time is longer. Only the right differential time can

reduce regulation time.

Range: 0.00～25.00s【0.00s】

P7.08 PID delay time constant

Note:

◆P7.08 set the output frequency delay time of PID.

P7.09 Residual margin

Range: 0.0～999.9【0.2】

Note:

◆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 Fig. 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.

◆If analog PID is selected, the setting of residual margin (P7.09) is the absolute value of

physical value, and it must match the measuring range. If speed PID is selected, the

setting of P7.09 is speed. As shown in Fig.5-7-1:

Time

Reference

Feedback

Residual margin

Opereation Freq.

Fig. 5-7-1 Residual margin diagram

P7.10 PID adjust characteristics

Range: 0,1【0】

0: Positive 1: Negative

Note:

◆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.

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