Mitsubishi Electronics MELSEC-F

/FX

3UC

PLC User's Manual - Analog Control Edition

PID Instruction (FNC 88)

M-19

4 Auto-Tuning

4.1 Limit Cycle Method

-4AD-PNK

-ADP

-4AD-TC

-ADP

PID Instruction

(FNC 88)

4.1.2 Auto-tuning procedure

1Set the forward or backward operation

Set the operation direction flag (bit 0) in the operation setting parameter (ACT) +1.

2Select the auto-tuning method (limit cycle method)

Set the auto-tuning method to ON (bit 6) in the operation setting parameter (ACT) +1.

(When bit 6 is set to OFF, the step response method is selected.)

3Set the auto-tuning execution flag to ON

Set the auto-tuning execution flag to ON (bit 4) in the operation setting parameter (ACT) +1.

4Set the input filter

Set the input filter in the operation setting parameter (ACT) +2.

5Set the sampling time

Set the sampling time .

6Set the Upper Limit Value (ULV)

Set the Upper Limit Value (ULV) of the output value (MV) in the operation setting parameter (ACT)

+26.

7Set the Lower Limit Value (LLV)

Set the Lower Limit Value (LLV) of the output value (MV) in the operation setting parameter (ACT)

+27.

8Set the threshold (hysteresis) (SHPV)

Set the threshold (hysteresis) width (SHPV) in the operation setting parameter (ACT) +25.

9Set the target value (SV)

Set the target value (SV) to in PID instruction.

10 Set the ON PID instruction command input to start auto-tuning

Auto-tuning is executed according to the measured value (PV).

↓

When auto-tuning is completed, the auto-tuning flag (bit 4 and bit 6) turns OFF in the operation set-

ting parameter (ACT) +1.