User`s manual

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MELSEC-Q
1 OVERVIEW
1.3 Forward Operation and Reverse Operation
(1) Forward operation is the action that increases the manipulated value when the process value
increases more than the set value.
(2) Reverse operation is the action that increases the manipulated value when the process value
is decreasing more than the set value.
(3) Forward operation and reverse action make the manipulated value larger as the difference
between the set value and the process value becomes larger.
(4) An example of process control performed by forward and reverse operations is shown in Fig.
1.2.
Temperature
Temperature
Time Time
Process value
Process value
Set value
Set value
Forward operation (for air conditioning) Reverse operation (for heating)
Fig. 1.2 Example of process control performed by forward and reverse operations