Dwyer SCZ10 - Manual (Page 13)

8. PID auto-tuning of the SCZ10
In order to decide each P, I, D value and ARW automatically, this system gives a fluctuation
to the controlled object to get a optimal value.
3 types of fluctuation below are automatically selected.
[ When the difference between setting value and processing temperature is large in rising]
When AT bias is set to 20°C(°F)), a fluctuation is given at the temperature 20°C(°F
[When control is stable]
A fluctuation is given at the setting value.
[ When the difference between the setting value and processing temperature is large when
temperature falls]
When AT bias is set to 20°C(°F), a fluctuation is given at the temperature 20°C(°F) ( higher than the
Setting
value
Temp.
Time AT
(1) (2) (3)
Temperature 20 °C(°F) lower
than the setting value
(4)
: AT Auto-tuning starting point
Calculating PID constant
PID contatnt calculated
Controlled by the PID
constant set by auto-tuning.
AT bias setting value
(1):
(2):
(3):
(4):
Temp.
Time AT
(1) (2) (3)
: AT Auto-tuning starting point
Setting
value
Calculating PID constant
PID constant calculated
Controlled by PID constant
set by auto-tuning (3):
(2):
(1):
Setting
value
Temp.
Time AT
(1) (2) (3)
: AT Auto-tuning starting point
(1): Calculating PID constacnt
(2): PID constant calculated
(3): Controlled by PID constant
set by auto-tuning
(4): AT bias setting value
(4)
Temperature 20 °C(°F) higher
than the setting value