Mitsubishi LE-40MTA-E, Instruction Manual

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7.1 Control of excessive sag or tension in material during start and stop
The following control is possible to limit the tension variation due to material inertia during machine start
and stop.
• The start timer is used to reduce the tension varia-
tion by shock at the time of starting. The control
output from starting the operation (after turning on
MC1) to entering the automatic control is fixed to
the stall value.
The stop timer, stop gain and stop bias are used to
limit the tension variation by material inertia when
the machine is decelerated to halt.
• During the time after the Run/stop input MC1 changes from ON
to OFF and before the stop timer times up, the following stop
gain and stop bias are valid. After that, the output before stop
(stall memory value) are generated.
Stop gain : The control output is adjusted to 5 to 400% of
the control output immediately before stop.
Stop bias : While the above stop gain is in effect, 0 to
50% of the rated output can be added. This
limits the tension variation by machine inertia
when the control output is small.
The control output by the total of the stop gain and the stop bias
is controlled to 100% or less.
• Two types of the control output in the stop timer operation can
be selected as follows. The feedback control is selected at the
time of shipping from the factory.
(1) The feedback control takes place while the stop timer is in
operation.
• This is selected when non-abrupt stop.
(2) The output is fixed while the stop timer is in operation.
• This is selected when the tension during the stop in (1) above is zero.
Select "Feedback" or "Fixed" on the "Stop T set" screen to select (1) or (2), respectively.
• Set the start timer.
• Select the output for the
stop timer.
• Set the stop gain.
• Set the stop bias.
• For the unwinding operation, set the stop gain to 100% or more so as not to let the tension become
zero.
• For the winding operation, set the stop gain to 100% or less and the stop bias to zero to avoid excessive
tension in the material.
• Refer to Section 11.6 "Minimum operating tension" to calculate the actual settings.
An approximate value is entered in general. A longer time is recommended.
1. Outline
MC1 input
Main shaft speed
Control output
Stall
Automatic
control
Stop gain
Stop bias
Stall
Stop timer
Start timer
ON OFF
OFF
Fix selected
Feed back selected
Stall
Stop
Stop timer
A
B
C=A
A : Output prior to stop
α β
B = A × + Tr ×
≤
Tr
100 100
α
: Stop gain
β
: Stop bias
Tr: Ratede output
C(=A) : Stall memory value
Unwinding use
2. Setting
S R T . T S E T S E T S T A R T T I M E R
S E T
→
# # . # s
T
S O P . T S E T S E T S T O P T I M E R
S E T
→
# # . # s : „ F E E D B A C K : F I X E D
T
S O P . G A I N S E T S T O P G A I N
S E T
→
# # # %
T
S O P . B I A S S E T S T O P B I A S
S E T
→
# # # %
T
T
Good to "FEED BACK"
T
T
7. Use of extensive functions