WIKA CS4L - Manual (Page 38)

Operating Instructions Temperature Indicating Controller CS4H / CS4L
V1.1 • 05/2006 - 38 -
8.2 PID auto-tuning of this controller
In order to decide each value of P, I, D and ARW automatically, this system forcibly fluctuates the object
being controlled.
(1) When the difference between the setting value and processing temperature is large as the
temperature rises.
Fluctuation is applied at the temperature 20 °C lower than the setting value.
(1) Calculating PID con-
stant
(2) PID constant
calculated
(3) Controlled by the PID
constant set by auto-
tuning.
(4) AT bias value
(Fig.
8.2-1)
(2) When the control is stable or when control temperature is within ±20 °C (°F) of setting value.
Fluctuation is applied at the setting value.
(1) Calculating PID con-
stant
(2) PID constant
calculated
(3) Controlled by the PID
constant set by
auto-tuning.
(Fig.
8.2.2)
(3) When the control temperature is 20 °C (°F) or higher than the setting value.
Fluctuation is applied at the temperature 20 °C (°F) higher than the setting value.
(1) Calculating PID const
ant
(2) PID constant calculat
ed
(3) Controlled by the PID
constant set by auto-t
uning.
(4) AT bias value
(Fig.
8.2.3)
Temperature 20 °C (°F) lower than the setting value
Temperature 20 °C (°F) higher than the setting value
(1) (2) (3)
(4)
AT starting point
Setting
value
Temperature
Time
AT starting point
(1) (2) (3)
Temperature
Setting
value
Time
AT starting point
(1) (2) (3)
(4)
Temperature
Setting
value
Time