Switching Pid According To Pv - YOKOGAWA UT Advanced UT32A User Manual

8.4 Switching PID
8.4.2 Switching PID According to PV
Description
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The PID switching according to PV is a function that switches between the groups of PID
parameters according to the PV.
The maximum number of PID groups to be switched is 8. (Set RP1 to RP3.)
This function is useful for reactors in which the chemical reaction gain changes
depending on the temperature.
The figure below shows an example of dividing the PV input range from the maximum
value to the minimum value into four zones by reference points 1 to 3. (Set RP1 to RP3.)
Maximum value of PV input range
Reference point 3
Reference point 2
Reference point 1
Minimum value of PV input range
The PV input range can be divided into the number of zones that is set in the reference
point.
Hysteresis at the time of zone switch can be set.
► Setpoint PD: 8.4.6 Setting Hysteresis at Time of Zone Switch
Reference deviation can be set at the same time.
► Reference deviation: 8.4.5 Switching PID according to Deviation (Reference Deviation)
If the PV is currently positioned at this point,
control is based on the PID of group 4.
PID of group 4
PID of group 3
PID of group 2
PID of group 1
Change in PV
IM 05P01D31-01EN