Instruction manual

136
PARAMETERS
(2) PID action overview
1) PI action
A combination of proportional control action (P) and integral control action (I) for
providing a manipulated variable in response to deviation and changes with
time.
[Operation example for stepped changes of process value]
Note: PI action is the sum of P and I actions.
2) PD action
A combination of proportional control action
(P) and differential control action (D) for providing a manipulated variable in
response to deviation speed to improve the transient characteristic.
[Operation example for proportional changes of process value]
Note:PD action is the sum of P and D
actions.
3) PID action
The PI action and PD action are combined
to utilize the advantages of both actions for control.
Note:The PID action is the sum of the P,
I and D actions.
Deviation Set point
Process value
Time
Time
Time
PI action
I action
P action
Deviation
Time
Time
Time
PD action
D action
P action
Set point
Process
value
Time
Time
Time
Deviation
P action
D action
PID action
Set point
Time
I action
Process
value
y=at
2
+bt+c
M4500E.book 136 ページ ２００５年２月２２日 火曜日 午後５時７分