National Instruments PID Control Toolkit 371685C-01 - Manual (Page 17)

Chapter 2 PID Algorithms
LabWindows/CVI PID Control Toolkit User Manual 2-8 ni.com
Note During tuning, the process remains under closed-loop PID control. It is not
necessary to switch off the existing controller and perform the experiment under open-loop
conditions. In the setpoint relay experiment, the SP signal mirrors the SP for the PID
controller.
Table 2-6. Tuning Formula under PI or PID Control (Slow)
Controller K
c
T
i
T
d
P 0.26T
p
/
τ
— —
PI 0.24T
p
/
τ
5.33
τ
—
PID 0.32T
p
/
τ
4.0
τ
0.8
τ