Chapter 11 Description of Parameter Settings|C200 Series
11-111
08 High-function PID Parameters This parameter can be set during operation.
Input Terminal for PID Feedback
Factory Setting:0
Settings 0: No function
1: Negative PID feedback: input from external terminal AVI (Pr.03-00)
2: Reserved
3: Reserved
4: Positive PID feedback from external terminal AVI (Pr.03-00)
Negative feedback means: +target value – feedback. It is used for the detection value will be
increased by increasing the output frequency.
Positive feedback means: -target value + feedback. It is used for the detection value will be
decreased by increasing the output frequency.
Common applications for PID control
; Flow control: A flow sensor is used to feedback the flow data and performs accurate flow
control.
; Pressure control: A pressure sensor is used to feedback the pressure data and performs
precise pressure control.
; Air volume control: An air volume sensor is used to feedback the air volume data to have
excellent air volume regulation.
; Temperature control: A thermocouple or thermistor is used to feedback temperature data for
comfortable temperature control.
; Speed control: A speed sensor or encoder is used to feedback motor shaft speed or input
another machines speed as a target value for closed loop speed control of master-slave
operation. Pr.10.00 sets the PID set point source (target value).
; PID control operates with the feedback signal as set by Pr.10.01 either 0~+10V voltage or
4-20mA current.
PID control loop:
¨
S)T
ST
1
(1K
d
i
p
×+
×
+
IM
¿¥
+
-
Setpoint
drive execute PID contro
output value
feedback signal
sensor
p
K : Proportional gain(P)
i
T : Integral time(I)
d
T : Derivative control(D) : Operator
Concept of PID control
1. Proportional gain(P):
the output is proportional to input. With only proportional gain control, there will always be
a steady-state error.
2. Integral time(I):
the controller output is proportional to the integral of the controller input. To eliminate the
Call 1(800)985-6929 for Sales
Call 1(800)985-6929 for Sales
To Next Page
Loading...
