Specifications

53
Constant Descriptions
8. PID Control
PID Control
PID control selection b5-01
Reference selection b1-01
Terminal A2 signal level selection H3-08
PID constant b5-02 to 10
（1）Reference selection setting
The frequency reference selected by b1-01 or the frequency
reference selected by multi-step speed reference 1, 2 or 3 will
be the reference selection for PID control. However, the
reference selection can be set as shown in the following table.
・The integral value is reset to 0 in the following cases:
・When stop command is input or during stop
・When multi-function input PID control cancel (set
value: 19) is selected, and terminal PID is set as
“
PID
control cancel
”
when
“
closed
”
・The upper limit of I can be set by b5-04.
When upgrading the control capacity by integration,
increase the value of b5-04.
If the control system vibrates and cannot be corrected by
adjusting the integral time or primary delay time
constant, decrease the b5-04 value.
・
The PID control can be canceled by the multi-function input
signal. The PID control is canceled by setting 19 in one of
H1-01 to 10, and closing the contact; the reference selection
signal is directly used as the frequency reference signal.
PID control makes the set reference selection coincide
with the feedback value (detected value). By combining
proportional control (P), integral control (I) and differential
control (D), PID control is enabled even for applications
(machine systems) having idle time.
Each control feature of PID control is as follows:
P control：Outputs the operation amount in proportion
with the deviation. However, the deviation
cannot be made zero only by P control.
I control ：
Outputs the operation amount obtained by
integrating the deviation. Effective to make the
feedback value coincide with the reference selection.
However, cannot follow up with rapid variation.
D control：Outputs the operation amount obtained by
differentiating the deviation.
（2）Detected value setting
The setting of the detected value can be selected from
the following table.
b5-01 Setting
0
1
2
3
4
No PID control
With PID control (D-control of deviation)
With PID control (D-control of feedback value)
With PID control (D-control of frequency
reference + PID output or deviation)
With PID control (D-control of frequency
reference + PID output or feedback value)
PID Control Function
Set b1-01 to 1 and H3-09 or H3-05 to C (PID
reference selection). At this time, set H6-01 to
1 (PID feedback value) and input the detected
value to pulse train input terminal RP.
Set b1-01 to 2 and bit of MEMOBUS register
000FH to 1, and register 0006H can be input as the
PID reference selection through communications.
Set b1-04 to 4 and H6-01 to 2 (PID reference
selection)
How to Set PID
Reference Selection
Input from Multi-
function Analog
Terminal A2 and A3
Input from MEMOBUS
Communication
Register 0006H
Input from Pulse Train
Input Terminal RP
Setting Conditions
＊ Terminal A2 current signal (4 to 20mA) or voltage signal (0 to 10V) can be used.
Terminal A2 current signal: H3-08 = 2
Terminal A2 voltage signal
: H3-08 = 0
When the voltage signal is used, turn OFF dip switch S1-2 on the
control board.
（ ）
＊
Set H3-09 or H3-05 to B (PID feedback value).
Set H6-01 to 1 (PID feedback value).
How to Input
Input from Multi-function
Analog Terminal A2 and A3
Input from Pulse Train
Input Terminal RP
Setting Conditions
＊ Same as the description for the above table.
＊
Reference
Selection
Detected
Value
D
Primary Lag
Time Constant
Offset
Output Gain
Frequency
Reference
D
LimiterLimiter
P
I
b5-05
b5-01
b5-05
b5-03
b5-04 b5-06
b5-08
b5-07
b5-10
b5-01
b5-01
b5-02
（Deviation） −
＋
＋ ＋
＋
＋
＋
＋
＋
1，3
1，3
2，4
2，4
3，4
0
1，2
ON
PID
OFF
PID Control Block Diagram
Cont
,
d