Mitsubishi Q Series User Manual page 42

3 SPECIFICATIONS
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REMARK
1) The time between the start and completion of auto tuning depends on the object
to be controlled.
2) You can confirm that auto tuning has been completed by checking that the auto
tuning status flag (Xn4, Xn5) has turned from on to off.
3) When the automatic backup setting after auto tuning of PID constants (buffer
memory address: 63, 95) is preset at AT start to be made valid, the PID
constants and loop disconnection detection judgment time are automatically
backed up by FeRAM on completion of auto tuning.
4) If the auto tuning does not complete after long period, make the following
approaches.
(a) When the measured value (PV) does not normally change
1) Check if load and external operation device are normally connected. If
not, normally connect them and then perform the auto tuning.
2) If using in the reverse action, check whether the set value is set not to
change the manipulated vale. If so, set the set value in the value to
control and perform the auto tuning.
(b) When the measured value (PV) are normally changing
1) If the response of the control target is slow, wait until the completion of the
auto tuning.
5) If the PID constants have not changed after the completion of the auto tuning,
check if the PID constants are constantly written by the sequence program. If
written, delete the sequence program of corresponding parts.
MELSEC-Q
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