YOKOGAWA UP35A, Руководство пользователя

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8-21
IM 05P02D41-01EN
Control Functions
8.4.2 Switching PID According to PV
Description
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 4. (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.)
PID of group 1
Minimum value of PV input range
Maximum value of PV input range
Reference point 1
Reference point 2
Reference point 3
PID of group 2
PID of group 3
PID of group 4
Change in PV
If the PV is currently positioned at this point,
control is based on the PID of group 4.
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)
Setting Details
Parameter
symbol
Name
Display
level
Setting range Menu symbol
ZON
Zone PID
selection
STD
0: Segment PID selection
1: Zone PID selection (selection
by PV)
2: Zone PID selection (selection
by target SP)
4: Zone PID selection (selection
by SP)
5: Local PID selection
CTL
RP1 to RP3
Reference point
1 to 3
STD
0.0 to 100.0% of PV input range
(EU)
(RP1 ≤ RP2 ≤ RP3)
ZONE
PID
PID number
(display only)
EASY
1 to 4, R: PID group for reference
deviation
MODE
Note1: A currently-used PID number is displayed for the parameter PID.
8
8.4 Switching PID