Instruction manual

PARAMETERS
120
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.
Time
Time
Time
Deviation
P action
D action
PD action
Set point
Process
value
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 P and I and D actions.
4) Reverse action
Increases the manipulated variable (output frequency) if deviation X (set point - process value) is positive,
and decreases the manipulated variable if deviation is negative.
X>0
X<0
+
-
Process value
Set point
[Heating]
Process value
Cold
→
fi up
Hot
→
fi down
Deviation
Set point
5) Forward action
Increases the manipulated variable (output frequency) if deviation X (set point - process value) is negative,
and decreases the manipulated variable if deviation is positive.
X>0
X<0
+
-
Set point
Too cold
→
fi down
Hot → fi up
Set point
[Cooling]
Process value
Process value
Deviation
Relationships between deviation and manipulated variable (output frequency)
Deviation
Positive Negative
Reverse action ÒÔ
Forward action ÔÒ