Mitsubishi MELSEC-F FX3U Series - Auto Tuning; Limit Cycle Method; Parameters Set in Auto Tuning (of Limit Cycle Method

G-18
4 Auto Tuning
FX 3U /FX 3UC Series PLC User's Manual - Analog Control Edition
PID Instruction (FNC 88)
4.1 Limit Cycle Method
4. Auto Tuning
This chapter describes the auto-tuning function of PID instruction.
The auto-tuning function will automatically set the important constants, such as the proportional gain and the
integral time, to ensure optimum PID control.
There are two auto-tuning methods: limit cycle method and step response method.
4.1 Limit Cycle Method
4.1.1 Parameters set in auto tuning (of limit cycle method)
Parameter Setting position
Proportional gain (K
P)
+3
Integral time (TI)
+4
Differential time (T
D)
+6
S 3
S 3 S 3
S 3 S 3