Mitsubishi Electric FR-A820-00046 (0.4K) Instruction Manual page 573

 Basic configuration of PID control
 Pr.128 ="10, 11" (deviation value signal input)
Set point
*1 Set "0" to Pr.868 Terminal 1 function assignment. When Pr.868 ≠ "0", PID control is invalid.
 Pr.128 = "20, 21" (measured value input)
Pr.133 or
terminal 2
0 to 5 VDC
(0 to 10 V, 4 to 20 mA)
*2 Note that the input of terminal 1 is added to the set point of terminal 2 as a set point.
*3 Set "0" to Pr.858 Terminal 4 function assignment. When Pr.858 ≠ "0", PID control is invalid.
 PID action outline
 PI action
PI action is a combination of proportional action (P) and integral action (I), and applies a manipulated amount according to the
size of the deviation and transition or changes over time.
[Example of action when the measured value changes in a stepped manner]
Deviation Set point
Measured value
P action
I action
PI action
(Note) PI action is the result of P and I actions being added together.
 PD action
PD action is a combination of proportional action (P) and differential action (D), and applies a manipulated amount according
to the speed of the deviation to improve excessive characteristics.
[Example of action when the measured value changes proportionately]
Set point
Measured value
P action
D action
PD
action
(Note) PD action is the result of P and D actions being added together.
572
5. PARAMETERS
5.14 (A) Application parameters
Deviation signal
+ -
Terminal 1
0 to 10 VDC
(0 to
To outside
Feedback signal (measured value)
Kp: Proportionality constant Ti: Integral time S: Operator Td: Differential time
*2
+ -
Set point
Terminal 4
Feedback signal (measured value)
Kp: Proportionality constant Ti: Integral time S: Operator Td: Differential time
Time
Time
Time
Deviation
Time
Time
Time
Inverter circuit
PID operation
1
*1
1+
Kp +Td S
Ti S
5 V)
Inverter circuit
PID operation
1
1+
Kp +Td S
Ti S
*3
4 to 20 mADC (0 to 5 V, 0 to 10 V)
Motor
Manipulated
variable
M
Motor
Manipulated
variable
M