Mitsubishi Electric MELSEC iQ-R Series User Manual page 123

Normal completion conditions
When the following conditions are satisfied, the following control or function is completed successfully and the control shifts to
the PID control.
■Normal completion conditions of the feed forward control
• A bottom has been detected
• The integral time has passed under the condition in which no disturbance has been detected at the disturbance judgment
position.
■Normal completion condition of the set value (SV) restoration adjustment
• The deviation (E) at the start of the disturbance suppression is 1% or lower of the maximum deviation, or the temperature
process value (PV) has reached the set value (SV).
• The deviation (E) is within the disturbance judgment position and the temperature process value (PV) is judged to be stable
enough.
Stop conditions
When the operating conditions are not satisfied or one of the following conditions is satisfied, the operation is stopped.
■Stop condition for only the feed forward control
• 'CH1 Feed forward control forced starting signal' (Un\G559) has been set to Feed forward control forced start (1), the
temperature process value (PV) responds in the reverse direction of the disturbance judgment position, and the value
exceeds the disturbance judgment width.
Ex.
The disturbance judgment position is -5.
Temperature
(+5 )
Set value
(SV)
Disturbance judgment
position (-5 )
'CH1 Feed forward control
OFF
forced starting signal' (Un\G559)
Operating status PID control
(1) Because the process value (PV) is larger than the reverse of the disturbance judgment position, the disturbance suppression is suspended and the control
shifts to the PID control.
• When 'CH1 Feed forward control forced starting signal' (Un\G559) has been set to Feed forward control forced start (1) and
no disturbance has been detected at the disturbance judgment position, 'CH1 Feed forward control forced starting signal'
(Un\G559) is changed to Feed forward control forced start stop (0).
When a disturbance has been detected at the disturbance judgment position, the operation does not stop
even though 'CH1 Feed forward control forced starting signal' (Un\G559) is changed to Feed forward control
forced start stop (0).
■Stop conditions for the set value (SV) restoration adjustment
The deviation (E) after a bottom exceeds the deviation (E) at the bottom.
Process value (PV)
ON
Disturbance
PID control
suppression
(1)
Time
1 FUNCTIONS
1.35 Disturbance Suppression Function
1
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