Nor-Cal SDC15 Controller - Manual (Page 69)

5-19
The following Figure shows the conceptual diagram expressing differences in
control result using the PID constant calculated by each AT type:
• For the AT Proportional band adjust (At-P), AT Integral time adjust (At-I), and
AT Derivative time adjust (At-d), the value that the PID constant calculated by
the AT is multiplied by each coefficient is written into the set value of the PID
constant. However, the coefficient must be a value in the PID constant setting
range.
Note
• Setting that the AT is activated for only the heat PID constant in the
Heat/Cool control:
50.0% <MV low limit at AT (At.oL) < MV high limit at AT (At.oH)
• Setting that the AT is activated for only the cool PID constant in the
Heat/Cool control:
MV low limit at AT (At.oL) < MV high limit at AT (At.oH) < 50.0%
For details about AT,
refer to AT stop/start (on page 5-8) and AT function (on page 5-
21) .
Chapter 5. DETAILED DESCRIPTION OF EACH FUNCTION
PV
Time
Difference in PV change when SP is changed.
SP
AT type = 1
(Immediate response)
AT type = 0 (Normal)
AT type = 2 (Stable)