YOKOGAWA UP35A, User Manual

Page: 81 / 412

6-20
IM 05P02D41-01EN
Manual PID Tuning Procedure
(1) In principle, auto-tuning must be used.
(2) Tune PID parameters in the order of P, I, and D. Adjust a numeric slowly by
observing the result, and keep notes of what the progress is.
(3) Gradually reduce P from a larger value. When the PV value begins to oscillate, stop
tuning and increase the value somewhat.
(4) Also gradually reduce I from a larger value. When the PV value begins to oscillate (with
long period), stop tuning and increase the value somewhat.
(5) Gradually increase D from a smaller value. When the PV value begins to oscillate (with
short period), stop tuning and lower the value slightly.
Reference Values for Manual Tuning of Temperature, Pressure, and Flow Rate
Setting range
(reference)
Initial value for tuning (reference)
Pressure
P 100 to 300% 200%
I 5 to 30 s 15 s
D OFF OFF
Flow rate
P 100 to 240% 150%
I 8 to 30 s 20 s
D OFF OFF
Temperature
(electric
furnace)
P 1 to 20% 5%
I 180 to 600 s 240 s
D 1/4 to 1/6 of I 60 s
6.3 Adjusting PID Manually