Mitsubishi FX3U-4AD User Manual page 444

FX /FX /FX PLC User's Manual - Analog Control Edition
3G 3U 3UC
PID Instruction (FNC 88)
3.2.3 Input filter (α): (S3)+2
PID control: Proportional operation, integral operation and differential operation
The input filter (α) is a software filter to reduce the fluctuation of the measured value (PV) caused by noise.
By setting this time constant of the filter according to the control target characteristics and noise level, the
effect of noise can be reduced.
• If the input filter value is too small, the filter effect is small.
• If the input filter value is too large, the input response is bad.
Because the input filter (α) is effective to the target value (SV), all of the proportional operation, integral
operation and differential operation are affected.
Actual
measured
value (PV)
Measured
value (PV)
processed by
input filter
L-12
3.2 Details of Parameters
Setting range: 0 to 99[%]
Pulse input by noise
Input amplitude
Input amplitude
processed by input filter
3 Parameter