Delta Electronics Programmable Logic Controller DVP-PLC - Manual (Page 398)

7 Application Instructions API 50-99
D V P - P L C A P P L I C AT I O N M A N U A L 7-114
1.5
1
0.5
0
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
PV=SV
K =10,K =8,K =0.2
P I D
Time (sec)
Note: This example is only for your reference. Please adjust your parameters to proper ones according to your
actual condition of the control system.
Application Examples:
Application 1 Using PID instruction in the pressure control system (use the diagram of Example 1).
Purpose: Enabling the control system to reach the target pressure.
Explanation: The system requires a gradual control. Therefore, the system will be overloaded or out of control if the
process progresses too fast.
Suggested solution:
Solution 1: Longer sampling time
Solution 2: Using delay instruction. See the figure below.
PID
MV
D5
SV
PV
D1
D1110
0
511
0
511
0V
10V
0rpm
rpm
3000
D1116
0
255
0V
5V
A
wave
B
wave
pressure
meter
Pressure
instruction
value (D0)
Pressure
instruction
delay
MV
converted
to
speed
Voltage
converted
to
instruction
value
Speed
converted
to
voltage
AC
motor
drive
280
0
0
280
250
200
150
100
50
t t
A wave B wave
Instruction
value Instruction
value
D2: Instruction interval value
D3: Instruction interval time
Adjusted by the user according to the actual condition