Delta AH500 Programming Manual page 345

3. To prevent the parameters which have been tuned automatically from disappearing after a
power cut, users have to store the parameters in the latched data registers when is
PID_MODE set to 1. The parameters which have been tuned automatically are not
necessarily suitable for every controlled environment. Therefore, users can modify the
parameters which have been tuned automatically. However, it is suggested that users only
modify the K or the K
I
4. The instruction should be used with many parameters. To prevent the improper control from
occurring, please do not set the parameters randomly.
Example 1: The use of the instruction PID in the position control (PID_MODE is set to 0 or 2.)
Po si tio n co mma nd (SV)
Example 2: The instruction PID is used with the AC motor drives. (PID_MODE is set to 0 or 2.)
Speed c ommand (S)
Acc eleration/Deceler ation
command ( SV)
Example 3: The use of the instruction PID in the temperature control (PID_MODE is set to 0 or 2.)
T emper atur e command ( SV)
Example 4: The steps of tuning the parameters used with the instruction PID
Suppose that the transfer function of the plant is the first-order function
sampling time Ts is 10 milliseconds. It is suggested that the steps of tuning the parameters are as
follows.
Step 1: First, set the K and the K
I
the target values and the process values. The results are shown in the diagram below.
.
D
PID
+
+
PID
PID
Actual temperature (PV)
to 0. Next, set the K
D
Ch a pt er 6 Ap p l i ed I ns t r uc t i ons
MV
AC motor
S+MV
driv es
Acc eleration/Deceler ation
output (MV)
Speed
detec tor ( P)
Actual ac celeration/
deceleration
(P V=S-P )
Heating (MV)
( )
G s =
to 5, 10, 20 and 40 successively, and record
P
Pla n t
En co d er
PV
Heater
T emper atur e
detec tor
b
, the SV is 1, the
s + a
6 - 1 7 7