Mitsubishi Electric MELSEC iQ-R Series User Manual page 46

Conditions in which the auto tuning ends in failure
The following shows the conditions.
■Shifting from the operation mode to the setting mode
When the mode is shifted from the operation mode to the setting mode ('Setting/operation mode command' (Y1) is turned
from ON to OFF), the auto tuning ends in failure. Note that an exception is when "Continue" has been set for "PID
continuation Flag" of "Control basic parameters" in "Application Setting.
■Setting change during auto tuning
When the following settings are changed during auto tuning, the auto tuning ends in failure.
• "Target Value(SV) Setting" of "Control basic parameters" in "Application Setting"
• "Upper limit output limiter" of "Limiter setting" in "Application Setting"
• "Lower limit output limiter" of "Limiter setting" in "Application Setting"
• "Cooling upper limit output limiter" of "Heating/cooling control setting" in "Application Setting"
• "Sensor Correction Value Setting" in "Application Setting"
• "Control output cycle setting" of "Control basic parameters" in "Application Setting"
• "Cooling control output cycle setting" of "Heating/cooling control setting" in "Application Setting"
• "Primary Delay Digital Filter Setting" in "Application Setting"
• 'CH1 AUTO/MAN mode shift' (Un\G518)
• "AT Bias" of "Auto tuning setting" in "Application Setting"
• "Normal Operation/Reverse Operation Setting" in "Application Setting"
• "Unused channel setting" of "Control basic parameters" in "Application Setting"
• "Cold Junction Temperature Compensation Selection" in "Application Setting"
• "Output Change Amount Limiter" of "Limiter setting" in "Application Setting"
• "Auto tuning mode setting" of "Auto tuning setting" in "Application Setting"
■Out of the temperature measuring range
If CH1 Temperature process value (PV) (Un\G402) exceeds the temperature measuring range (CH1 Input range upper limit
(Un\G401, b0) or CH1 Input range lower limit (Un\G401, b1) is ON), the auto tuning ends in failure.
■Time for the temperature process value (PV) to reach the set value (SV) for the first time or a
half cycle of the hunting of the temperature process value (PV)
When the following time exceeds the value set for "Auto tuning forced termination time setting" of "Auto tuning setting" in
"Application Setting," the auto tuning ends in failure.
• Time from the start of the auto tuning until 'CH1 Temperature process value (PV)' (Un\G402) reaches the set value (SV) for
the first time
• A half cycle of the hunting of 'CH1 Temperature process value (PV)' (Un\G402)
■Calculation value of PID constants after auto tuning (in the R mode)
When a calculation value of PID constants after auto tuning exceeds one of the following ranges, the auto tuning ends in
failure.
• 'CH1 Proportional band (P) setting' (Un\G431): 0.1 to the full scale of the input range ( ())
• 'CH1 Integral time (I) setting' (Un\G432): 1 to 3600 (s)
• 'CH1 Derivative time (D) setting' (Un\G433): 0 to 3600 (s)
1 FUNCTIONS
44
1.11 Auto Tuning Function