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-23
5 Example of Practical Programs (for Step Response Method)
5.1 Example: System and operation
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
)
)
5.
Example of Practical Programs (for Step Response Method)
The following is an example of a program for the operation application system shown below.
5.1
Example: System and operation
System configuration
Setting contents
1. Operation of the electric heater
1) During PID control
2) During auto-tuning: When the output is 90% of the maximum output
Item
During auto-
tuning
During PID
control
Target value
500 (+50
°C)
500 (+50
°C)
Pa
rameters
Sampling time (T
S
)
3000 ms
500 ms
Input filter (
α)
+2
70%
70%
Differential gain (K
D
)
+5
0%
0%
Output value upper limit
+22
2000
(2 seconds)
2000
Output value lower limit
+23
0
0
Operation direction
(ACT)
(ACT)
Input variation alarm
bit 1 of
+1
Not provided
Not provided
Output variation alarm
bit 2 of
+1
Not provided
Not provided
Output value upper/lower limit setting
bit 5 of
+1
Provided
Provided
Output value
1800
According to
operation
Temperature
chamber
Shielded compensating
conductor
Temperature sensor
(Thermocouple)
Error indication
X010: Auto-tuning command
X011: PID control command
Electric heater
FX
2N
-16EYT-
ESS/UL
*1
FX
2N
-4AD-
TC
FX
3U
-32MR/
ES
Y21
Y20
COM
X11
X10
ch2
*1: Since turning on/off is frequently carried out, be sure to use the
transistor outputs.
S
1
S
3
S
3
S
3
S
3
S
3
S
3
S
3
S
3
D
2 sec (2000 ms)
<cycle>
D502
× 1 ms <ON duration>
OFF
2 sec (2000 ms)
ON
ON
ON
ON
ON
2 sec (2000 ms)
2 sec (2000 ms)
2 sec (2000 ms)
2 sec (2000 ms)
1.8 sec (1800 ms)
1.8 sec (1800 ms)
1.8 sec (1800 ms)