Mitsubishi Electric FR-A700 Technical Manual page 368

2.20.4 PID control [Pr. 127 to 134, 575 to 577*]
The inverter can be used to exercise process control, e.g.
flow rate, air volume or pressure.
The terminal 2 input signal or parameter setting is used as
a set point and the terminal 4 input signal used as a
[Pr.] Name
PID control
automatic
127
switchover
frequency
PID action
128
selection
PID
proportional
129 *1
band
PID integral
130
*1
time
131 PID upper limit
132 PID lower limit
PID action set
133 *1
point
PID differential
134
*1
time
Initial Setting
Value Range
Set the frequency at which the control is automatically changed to
0 to 400Hz
PID control.
9999
9999 Without PID automatic switchover function
0 PID action is not performed
10 PID reverse action
11 PID forward action
A700
20 PID reverse action
21 PID forward action
F700
40 PID reverse action
10
41 PID forward action
42 PID reverse action
E700
43 PID forward action
D700
50 PID reverse action
0
51 PID forward action
60 PID reverse action
61 PID forward action
If the proportional band is narrow (parameter setting is small), the
manipulated variable varies greatly with a slight change of the
0.1 to 1000% measured value. Hence, as the proportional band narrows, the
100%
response sensitivity (gain) improves but the stability deteriorates,
e.g. hunting occurs. Gain Kp = 1/proportional band
9999 No proportional control
For deviation step input, time (Ti) required for only the integral (I)
action to provide the same manipulated variable as that for the
0.1 to 3600s
1s
proportional (P) action. As the integral time decreases, the set
point is reached earlier but hunting occurs more easily.
9999 No integral control.
Set the upper limit value. If the feedback value exceeds the
0 to 100% setting, the FUP signal is output. The maximum input (20mA/5V/
9999
10V) of the measured value (terminal 4) is equivalent to 100%.
9999 No function
Set the lower limit value. If the measured value falls below the
setting range, the FDN signal is output. The maximum input
0 to 100%
9999
(20mA/5V/10V) of the measured value (terminal 4) is equivalent to
100%.
9999 No function
0 to 100% Used to set the set point for PID control.
9999
9999 Terminal 2 input is the set point.
For deviation ramp input, time (Td) required for providing the
manipulated variable for the proportional (P) action only. As the
0.01 to 10.00s
9999
differential time increases, greater response is made to a deviation
change.
9999 No differential control.
common
(common)
(*[Pr. 575 to 577] are not available for
feedback value to constitute a feedback system for PID
control.
Description
Deviation value signal input
(terminal 1 )
Measured value (terminal 4)
Set value (terminal 2 or [Pr. 133])
For dancer control
Addition
set point ([Pr. 133]),
method: fixed
measured value (terminal 4),
main speed (frequency
Addition
command of the operation
method: ratio
mode)(Refer to page 411)
Deviation value signal input
(L W , CC-Link communication)
ON ORKS
Measured value and set point input
(L W , CC-Link communication)
ON ORKS
402
PARAMETER
.)
E700
Available
Inverters
A700
E700 D700
F700
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