YOKOGAWA UTAdvanced UT55A, User Manual

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8-80
IM 05P01C31-01EN
8.2.5 PD Control (Stable Control in Which a Setpoint is not Exceeded)
Description
This control type performs control in which integral action (I action) is excluded from PID
action.
Set the integral time (I or Ic) to OFF.
It is useful when stable control in which a setpoint is not exceeded is desired for integral
processes in which constant flows are delivered.
The following shows the PID control computation formula.
MR ∆ PV
d
e
P
OUT +



 


+ = •
dt
100
Td
where OUT: control output, e: deviation (PV-SP), P: proportional band, Td: derivative time,
∆PV: PVn-PVn-1 (n-1: value before one control period), and MR: manual reset
The following table shows combination of PD control and control mode (CTLM).
Control mode (CTLM)
SGL CAS1 CAS2 CAS BUM PVSW PVSEL PVHD
PD control √ N/A √ √ √ √ √ √
√: Available, N/A: Not available
The following table shows combination of PD control and output method.
Output method
Current
output
Time
proportional
output
ON/OFF
output
Position
proportional
output
PD control √ √ N/A √
√: Available, N/A: Not available
Setting Details
Parameter
symbol
Name
Display
level
Setting range Menu symbol
P Proportional band EASY
0.0 to 999.9%
When 0.0% is set, it operates as 0.1%.
PID
D Derivative time EASY
OFF: Disable
1 to 6000 s
MR Manual reset EASY -5.0 to 105.0%
PIDG.
Number of PID
groups
STD 1 to 8 CTL
Note1: The PID number (1 to 8, or R) is displayed on Group display while the parameter P, D, or MR is displayed.
Note
When changing the setpoint of the parameter PIDG., if the setpoint of the parameter PIDN
which belongs to the SP menu is larger than that of the parameter PIDG., the PIDN setpoint is
changed to the PIDG. setpoint.
8.2 Setting Control Type (CNT)