Mitsubishi FX3U-4AD User Manual

L-10
3 Parameter
FX 3G /FX 3U /FX 3UC PLC User's Manual - Analog Control Edition
PID Instruction (FNC 88)
3.2 Details of Parameters
3.2.2 Operation setting (ACT):(S3)+1
Setting range: OFF = forward operation, ON = backward operation
1. Forward operation or backward operation: +1, bit 0
Select the PID control direction (forward or backward).
• During auto-tuning for the limit cycle method
It is necessary to set the PID control direction (forward or backward) for auto-tuning.
• During auto-tuning for the step response method
The PID control direction (forward or backward) is not required as, the direction is automatically set when
auto-tuning is complete.
Forward operation: +1, bit 0 = 0
As the measured value (PV) becomes larger than the target value (SV), the output (MV) increases.
For example, cooling is a forward operation.
<Cooling>
Backward operation: +1, bit 0 = 1
As the measured value (PV) becomes smaller than the target value (SV), the output (MV) increases.
For example, heating is a backward operation.
<Heating>
Relationship between the forward/backward operation and the output (MV), measured value (PV) and
target value (SV)
The relationship is as follows.
S 3
S 3
Time
Target value (SV)
Measured value (PV)
Temperature
S 3
Time
Target value (SV)
Measured value (PV)
Temperature
Output (MV)
Backward
operation
Target value (SV)
Forward
operation
Measured value (PV)

Mitsubishi FX3U-4AD Specifications

General

Brand	Mitsubishi
Model	FX3U-4AD
Category	Controller
Language	English