Mitsubishi Electronics MELSEC-F Manuel D’Utilisation
FX
3G
/FX
3U
/FX
3UC
PLC User's Manual - Analog Control Edition
PID Instruction (FNC 88)
M-19
4 Auto-Tuning
4.1 Limit Cycle Method
K
FX
3U
-4A
D
D
-P
NK
-A
D
P
L
FX
3U
-4AD
-TC
-
A
D
P
M
PI
D
In
st
ru
ctio
n
(F
N
C
88
)
)
4.1.2
Auto-tuning procedure
1
Set the forward or backward operation
Set the operation direction flag (bit 0) in the operation setting parameter (ACT)
+1.
2
Select 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.)
3
Set the auto-tuning execution flag to ON
Set the auto-tuning execution flag to ON (bit 4) in the operation setting parameter (ACT)
+1.
4
Set the input filter
Set the input filter in the operation setting parameter (ACT)
+2.
5
Set the sampling time
Set the sampling time
.
6
Set the Upper Limit Value (ULV)
Set the Upper Limit Value (ULV) of the output value (MV) in the operation setting parameter (ACT)
+26.
7
Set the Lower Limit Value (LLV)
Set the Lower Limit Value (LLV) of the output value (MV) in the operation setting parameter (ACT)
+27.
8
Set the threshold (hysteresis) (SH
PV
)
Set the threshold (hysteresis) width (SH
PV
) in the operation setting parameter (ACT)
+25.
9
Set 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)
ting parameter (ACT)
+1.
S
3
S
3
S
3
S
3
S
3
S
3
S
3
S
3
S
3
S
3
S
3
S
3
S
3
S
3
S
3
S
1
S
3
S
3