Mitsubishi A1SD75P1-S3, User Manual

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MELSEC-A
8 ZERO POINT RETURN CONTROL
8.2.7 Zero point return method (5): Count method 1)
The following shows an operation outline of the "count method 1)" zero point return
method.
Operation chart
1)
The machine zero point return is started.
(The machine begins the acceleration designated in "
Pr.53
Zero point return acceleration time selection", in the
direction designated in "
Pr.46
Zero point return direction". It then moves at the "
Pr.48
Zero point return speed" when
the acceleration is completed.)
2) The machine begins decelerating when the near-point dog ON is detected.
3) The machine decelerates to the "
Pr.49
Creep speed", and subsequently moves at that speed.
4)
On detection of the first zero point signal after the axis has traveled the movement amount set in the "
Pr.52
Setting for
the movement amount after near-point dog ON" after the near-point dog ON, the pulse output from the AD75 stops and
the "deviation counter clear output" is output to the drive unit.
5)
After a "deviation counter clear output" is output to the drive unit, the zero point return complete flag (
Md.40
Status: b4)
turns from OFF to ON, and the zero point return request flag (
Md.40
Status: b3) turns from ON to OFF.
t
ON
OFF
ON
OFF
OFF
ON
0
V
ON
Pr. 49 Creep speed
Pr. 48 Zero point return speed
Pr. 52 Setting for the movement amount
after near-point dog ON
Md.44 Movement amount after near-point dog ON
Zero point signal
Near-point dog OFF
Machine zero point return start
(Positioning start signal)
Standing by In zero point return
Md.35 Axis operation status
Inconsistent
Value the machine moved is stored
Zero point address
Value of *1.
Deviation counter clear output
Standing by
Inconsistent
Zero point return request flag
[ Md.40 Status : b3]
Zero point return complete flag
[ Md.40 Status : b4]
Md.30 Machine feed value
Md.44 Movement amount
after near-point dog ON
Md.29 Current feed value
* 1
1) 2) 3) 4) 5)
Adjust the movement amount after
activation at the near-point dog to
the center of the high zero point
signal interval as far as possible.
If the movement amount setting
after activation at the near-point dog
interferes with the zero point signal,
the machine zero point return stopping
position may deviate by a revolution of
the servomotor.
First zero point after travel by " Pr. 52
Setting for the movement amount
after near-point dog ON"
There is no problem even if deactivation at the
near-point dog occurs during machine zero point
return.
However, deactivation at the near-point dog
should be as far from the zero position as
possible, due to the following reason.
If deactivation at the near-point dog occurs at
the end of machine zero point return, the motor
is not stopped in the second action until the upper
or lower limit is reached when repetitive machine
zero point return cycles occur. If the zero point
return retry function has been invalidated, an
error is caused upon detection of the limit.
One
servomotor
rotation
Fig. 8.11 Count method1) machine zero point return
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