Nor-Cal SDC15 Controller User 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%

• 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

Time

Difference in PV change when SP is changed.

AT type = 1
(Immediate response)

AT type = 0 (Normal)

AT type = 2 (Stable)