1-82 Min Speed for Function at Stop [Hz]
Range:
Function:
Size related
*
[ 0 - 500.0
Hz]
Set the output frequency at which
to activate
.
1-83 Precise Stop Function
Option:
Function:
NOTICE
This parameter cannot be adjusted while
the motor is running.
Valid for FC 302 only.
[0]
*
Precise
ramp
stop
Only optimal when the operational speed, for
example the operational speed of a conveyor belt,
is constant. This is an open-loop control. Achieves
high repetitive precision at the stop point.
[1] Cnt stop
with
reset
Counts the number of pulses, typically from an
encoder, and generates a stop signal after a pre-
programmed number of pulses, defined in
parameter 1-84 Precise Stop Counter Value
, has
been received at
terminal 29
or
terminal 33
.
This is direct feedback with one-way closed-loop
control.
The counter function is activated (starts timing) at
the edge of the start signal (when it changes from
stop to start). After each precise stop, the number
of pulses counted during ramp down to 0 RPM is
reset.
[2] Cnt stop
w/o
reset
Same as
[2] Cnt stop with reset
but the number of
pulses counted during ramp down to 0 RPM is
deducted from the counter value entered in
parameter 1-84 Precise Stop Counter Value
This reset function can be used to compensate for
the extra distance done during ramping down
and to reduce the impacts of gradual wear of
mechanical parts.
[3] Speed
comp
stop
Stops at precisely the same point, regardless of
the present speed. The stop signal is delayed
internally when the present speed is lower than
the maximum speed (set in
parameter 4-19 Max
Output Frequency
).
The delay is calculated on the basis of the
reference speed of the frequency converter and
not on the basis of the actual speed. Make sure
that the frequency converter has ramped up
before activating the speed compensated stop.
[4] Com cnt
stop
w/rst
Same as
Speed comp stop
but after each precise
stop, the number of pulses counted during ramp
down to 0 RPM is reset.
[5] Comp
cnt stop
w/o r
Same as
Speed comp stop
but the number of
pulses counted during ramp down to 0 RPM is
deducted from the counter value entered in
parameter 1-84 Precise Stop Counter Value
1-83 Precise Stop Function
Option:
Function:
This reset function can be used to compensate for
the extra distance done during ramping down
and to reduce the impacts of gradual wear of
mechanical parts.
The precise stop functions are advantageous in
applications where high precision is required.
If using a standard stop command, the accuracy is
determined by the internal task time. That is not the case
when using the precise stop function. It eliminates the task
time dependence and increases the accuracy substantially.
The frequency converter tolerance is normally given by its
task time. However, by using its special precise stop
function, the tolerance is independent of the task time
because the stop signal immediately interrupts the
execution of the frequency converter program. The precise
stop function gives a highly reproducible delay from the
stop signal is given until the ramping down starts. Run a
test to find this delay as it is a sum of sensor, PLC,
frequency converter, and mechanical parts.
To ensure optimum accuracy, there should be at least 10
cycles during ramping down, see:
•
Parameter 3-42 Ramp 1 Ramp Down Time
.
•
Parameter 3-52 Ramp 2 Ramp Down Time
.
•
Parameter 3-62 Ramp 3 Ramp down Time
.
•
Parameter 3-72 Ramp 4 Ramp Down Time
.
The precise stop function is set up here and enabled from
DI at terminal 29 or terminal 33.
1-84 Precise Stop Counter Value
Range:
Function:
100000
*
[0 -
999999999 ]
Enter the counter value to be used in
the integrated precise stop function,
parameter 1-83 Precise Stop Function
.
The maximum permissible frequency at
terminal 29 or 33 is 110 kHz.
NOTICE
Not used for selections
[0] Precise
ramp stop
and
[3] Speed comp stop
in
.
1-85 Precise Stop Speed Compensation Delay
Range:
Function:
10 ms
*
[0 -
100 ms]
Enter the delay time for sensors, PLCs, and so
on for use in
. In speed compensated stop mode,
the delay time at different frequencies has a
major influence on the stop function.
Parameter Descriptions
Programming Guide
MG33MP02
Danfoss A/S © 10/2018 All rights reserved.
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Содержание VLT AutomationDrive FC 302
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