Auto Tuning Setting Function - Mitsubishi Electric MELSEC-Q Series User Manual

3 SPECIFICATIONS

3.2.2 Auto tuning setting function

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This function sets the auto tuning mode according to the control target by setting AT
differential gap (buffer memory address: 46, 78) and AT additional lag (buffer
memory address: 47, 79).
AT differential gap and AT additional lag can be set within the setting range.
However, almost all control targets are accepted by the following setting of "Standard
mode" and "Fast response mode".
(1) Standard mode (Default)
This mode is compatible with almost all control targets.
Especially, this mode is effective for control targets which give an extremely
slow response or which may be affected by noise or disturbance.
However, when the control target that either the on or off time during auto
tuning is about 10 seconds only, slow-response (low-gain) PID constants may
be calculated. In this case, fast-response PID constants can be calculated by
executing auto tuning in the fast response mode.
To perform auto tuning in the standard mode, set AT differential gap and AT
additional lag to 10 (0.1s).
(2) Fast response mode
This mode calculates faster-response (higher-gain) PID constants for the
control targets which gives a fast response that the on or off time during auto
tuning is about 10 seconds only.
Note that the gains of the calculated PID constants may become so high that
the measured value (PV) may oscillate near the set value (SV). In this case,
execute auto tuning in the standard mode.
To perform auto tuning in the fast response mode, set AT differential gap and
AT additional lag to 1 (0.01s).
MELSEC-Q
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