Mitsubishi Electric MELSEC iQ-R Series User Manual page 47

■Calculation value of PID constants after auto tuning (in the Q compatible mode)
When a calculation value of PID constants after auto tuning exceeds one of the following ranges, the auto tuning ends in
failure.
• "Proportion Belt (P) Setting" of "Control basic parameters" in "Application Setting": 0.1 to 1000.0%
• "Integration Time (I) Setting" of "Control basic parameters" in "Application Setting": 1 to 3600s
• "Differentiation Time (D) Setting" of "Control basic parameters" in "Application Setting": 0 to 3600s
When the auto tuning ends in failure due to the calculation value of PID constants as described above, check
the system configuration. (Select a suitable heater capacity or others.)
When temperature control points are close between channels, the auto tuning may not be completed due to a
heat interruption if the auto tuning is executed to all channels in a batch. In this case, execute the auto tuning
by one channel to prevent from receiving heat interruptions.
■Change of the upper limit setting limiter or lower limit setting limiter and AT point
When the AT point goes out of the setting range due to a change in one of the following parameters, the auto tuning ends in
failure.
• "Upper Limit Setting Limiter" of "Limiter setting" in "Application Setting"
• "Lower Limit Setting Limiter" of "Limiter setting" in "Application Setting"
■Other conditions (in the R mode)
In addition to the conditions described above, if any of the following conditions is satisfied, the auto tuning ends in failure.
• 'CH1 PID control forced stop command' (YC) has been turned from OFF to ON.
• A hardware failure has occurred.
• In the standard control, 'CH1 Proportional band (P) setting' (Un\G431) has been set to 0 (0 ()). (The two-position
control has been set.)
• In the heating-cooling control, 'CH1 Heating proportional band (Ph) setting' (Un\G431) has been set to 0 (0 ()). (The
two-position control has been set.)
■Other conditions (in the Q compatible mode)
In addition to the conditions described above, if any of the following conditions is satisfied, the auto tuning ends in failure.
• 'CH1 PID control forced stop command' (YC) has been turned from OFF to ON.
• A hardware failure has occurred.
• In the standard control or heating-cooling control, 0% has been set for "Proportion Belt (P) Setting" of "Control basic
parameters" in "Application Setting." (The two-position control has been set.)
1 FUNCTIONS
1.11 Auto Tuning Function
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