Dancer Control (Pr. 44, Pr. 45, Pr. 128 To Pr. 134) - Mitsubishi Electric FR-D720-0.4K Instruction Manual

4.20.2 Dancer control (Pr. 44, Pr. 45, Pr. 128 to Pr. 134)

Performs PID control by feedbacking the position detection of the dancer roller, controlling the dancer roller is in the
specified position.
Parameter
Name
Number
Second
44 acceleration/
deceleration time
Second
45
deceleration time
PID action
128
selection
PID proportional
129 ∗1
band
130 ∗1
PID integral time
131 PID upper limit
132 PID lower limit
PID action set
133 ∗1
point
PID differential
134 ∗1
time
The above parameters can be set when Pr.160 Extended function display selection = "0". (Refer to page 163)
∗1
Pr. 129, Pr. 130, Pr. 133 and Pr.134 can be set during operation. These can also be set independently of the operation mode.
Special operation and frequency control
Setting
Initial Value
Range
3.7K or lower 5s
5.5K and 7.5K 10s 0 to 3600s
11K and 15K 15s
0 to 3600s
9999
9999
0
0.1 to 1000%
100%
9999
0.1 to 3600s
1s
9999
0 to 100%
9999
9999
0 to 100%
9999
9999
0 to 100%
9999
9999
0.01 to 10s
9999
9999
Description
This parameter is the acceleration time of the main
speed during dancer control. It will not function as
second acceleration/deceleration time.
This parameter is the deceleration time of the main
speed during dancer control. It will not function as
second deceleration time.
0 PID action is not performed
PID reverse
20
action
Measured value (terminal 4)
Set value (terminal 2 or Pr. 133)
PID forward
21
action
PID reverse Addition
40
method: fixed For dancer control
action
Addition
PID forward
41
action method: fixed
Addition
PID reverse
42
action method: ratio
Addition
PID forward
43
action
method: ratio
If the proportional band is narrow (parameter
setting is small), the manipulated variable varies
greatly with a slight change of the measured value.
Hence, as the proportional band narrows, the
response sensitivity (gain) improves but the
stability deteriorates, e.g. hunting occurs. Gain Kp
= 1/proportional band
No proportional control
When deviation step is input, time (Ti) is the time
required for integral (I) action to provide the same
manipulated variable as the proportional (P) action.
As the integral time decreases, the set point is
reached earlier but hunting occurs more easily.
No integral control.
Maximum value
If the feedback value exceeds the setting, the FUP
signal is output. The maximum input (20mA/5V/
10V) of the measured value (terminal 4) is
equivalent to 100%.
No function
Minimum value
If the measured value falls below the setting range,
the FDN signal is output. The maximum input
(20mA/5V/10V) of the measured value (terminal 4)
is equivalent to 100%.
No function
Used to set the set point for PID control.
Always 50%
For deviation ramp input, time (Td) required for
providing only the manipulated variable for the
proportional (P) action.
As the differential time increases, greater response
is made to a deviation change.
No differential control.
set point (Pr. 133),
measured value
(terminal 4)
main speed (speed
command of the
operation mode)
4
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