Mitsubishi MELSEC-F FX3U Series

FX 3U /FX 3UC Series PLC User's Manual - Analog Control Edition
PID Instruction (FNC 88)
G-23
5 Example of Practical Programs (for Step Response Method)
5.1 Example: System and operation
A
Common Items
B
FX
3UC
-4AD
C
FX
3U
-4AD-ADP
D
FX
3U
-4DA-ADP
E
FX
3U
-4AD-PT
-ADP
F
FX
3U
-4AD-TC
-ADP
G
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
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)
Parameters
Sampling time (TS)
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
00
Operation direction
(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
Y21Y20COM
X11X10
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 ONON
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)