42
When checking or directly inputting the PID value, press the button of the zone you want in the High
Temp. Room or the Low Temp. Room in [Fig. 58], and [Fig. 59] or [Fig. 60] is indicated. You can set
the parameter by pressing the PID button of each pertinent zone.
● PID Parameter Check and Manual Setup
[Fig. 58] PID Zone Setup Screen
High Level
℃
Middle Level
Low Level
Time
-200.0
1700.0
PID-4
PID-3
PID-2
PID-1
Proportional Band
(P-Band)
It means the temperature range, in which the output calculated comes to fall
within 100 %, in the control that determines the output in proportion to the
deviation between the SV and the PV.
When the proportional band is wide, the control output on the deviation is small
thus it takes longer to reach the SV when the proportional band is narrow, the
control output is large thus it takes shorter to reach the SV, but the overshoot
gets increased.
Integral Time
(I-Time)
It is a control item that increases the output gradually with the sum of the
accumulated deviations, as the occurrence of deviation cannot be blocked with
only the proportional control (because the temperature does not be maintained
when the output is 0). When the time value is large, the reflected ratio is small
thus, it takes longer to reduce the deviation when the time value is small, the
reflected ratio is big thus, the deviation reduces faster, but the occurrence of
hunting is caused.
Derivative Time
(D-Time)
It is a control item that adds the control output in the direction to decrease
the changes in proportion to the rate of change of deviation. Hence, if errors
increasing suddenly, a correction motion is performed as a resistance to that.
The greater the derivative time, the stronger the correction motion.
