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4.12 PID functions:PA.00-PA.28
PID control is a general process control method. By performing proportional, integral and differential
operations on the difference between the feedback signal and the target signal, it adjusts the output
frequency and constitutes a feedback system to stabilize the controlled counter around the target value.
It is applied to process control such as flow control, pressure control and temperature control. The
following figure shows the principle block diagram of PID control.
Code
Description
Setting range
Defa
ult
Restric
tions
PA.00
PID setting source
PA.01 setting
0
0
☆
AI1
1
AI2
2
AI3( keyboard potentiometer)
3
Pulse(DI5)
4
Communication setting
5
Multi-reference
6
PA.01
PID digital setting
0.0%~100.0%
50.0%
☆
PA.00 is used to select the channel of target process PID setting. The PID setting is a relative
value and ranges from 0.0% to 100.0%. The PID feedback is also a relative value. The purpose of
PID control is to make the PID setting and PID feedback equal.
PA.02
PID feedback source
AI1
0
0
☆
AI2
1
AI3( keyboard potentiometer)
2
Pulse(DI5)
3
Communication setting
4
AI1
5
AI1+AI2
6
MAX(|AI1|, |AI2|)
7
+
-
Target
Feedback
PID output
P
1
Td*s+1
Ti
S
1
1
