Mitsubishi Electric MELSEC iQ-R Series User Manual page 55

Precautions
• Before starting the temperature control using the temperature control module, power ON a controlled object such as a
heater. When the temperature control is started while the heater power supply is OFF, the PID constants for the response
different from original characteristics are calculated by the self-tuning.
Temperature process value (PV)
Set value (SV)
Original response
Control start
• Do not use the self-tuning function for controlled objects where a great disturbance (uncontrollable disturbance) occurs
periodically. Doing so may cause improper PID constants to be calculated by the self-tuning. When the self-tuning function
is used for such objects, improper PID constants are set and the response for the set value (SV) change or disturbance
becomes slow. Use the disturbance suppression function for the controlled objects where a disturbance occurs periodically.
( Page 117 Disturbance Suppression Function)
Response of when a heater is powered on
after the temperature control module starts
temperature control
Heater powered ON
Time
1 FUNCTIONS
1.12 Self-tuning Function
1
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