Mitsubishi Electric FR-E 500 Instruction Manual page 151

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.
Set point
Feedback signal
(Process value)
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.
Set point
Feedback signal
Relationships between deviation and manipulated variable (output frequency)
Reverse
action
Forward
action
[Heating]
Cold
X>0
+
X<0
Hot
-
[Cooling]
X>0
Too cold
+
X<0
Hot
-
(Process value)
Deviation
Positive Negative
) *
* )
Deviation
up
down
Process value
Process value
down
up
Deviation
136
PARAMETERS
Set point
Set point