Mitsubishi Electric MELSEC-Q Series User Manual page 45

3 SPECIFICATIONS
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2) Forced PID control stop command (YnC, YnD) has been turned on.
3) The mode is changed to other than the normal control mode (setting
mode, manual control mode1/2, program control mode). (Exception:
when PID continuation flag (buffer memory address: 169) is set to
"Continue" and the mode is changed to the setting mode)
4) A hardware failure has been detected.
5) The measured value has exceeded the input range.
6) The following time has exceeded 2 hours.
• Time elapsed from the auto tuning start until the set value is
reached at the first time.
• A half of the hunting cycle
7) The calculated PID constants have exceeded any of the following
ranges.
Proportional band (P): 0.1 to full-scale ( )
Integral time (I): 0.1 to 3276.7 (s)
Derivative time (D): 0.0 to 3276.7 (s)
(3) Operation at termination of auto tuning
(a) Operation at normal termination
• Auto tuning status flag (Xn4, Xn5) turns off.
• The PID constants are set.
• Loop disconnection detection judgment time (buffer memory address: 59,
91) is set. (If 0 is set when the auto tuning starts, the value remains
unchanged.)
(b) Operation at abnormal termination
• Auto tuning status flag (Xn4, Xn5) turns off.
• The PID constants and loop disconnection judgement time are not set.
• The error code and factor code of the corresponding error are stored in
Error code (buffer memory address: 0), and the ERR. LED flashes.
(Exception: when Forced PID control stop command (YnC, YnD) are
turned on and when the mode is changed to the setting mode)
For details of error codes and factor codes, refer to Section 8.1.
(4) Adjustment after auto tuning
(a) Specific readjustment is not required for the PID constants calculated by
auto tuning.
(b) Use Control response parameter (buffer memory address: 49, 81) to
change the control response for the PID constants calculated by auto tuning.
0.1 to 1000.0 (%)
MELSEC-Q
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