Example Of Practical Programs (For Step Response Method; Example: System And Operation - Mitsubishi MELSEC-F FX3U Series User Manual

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