Disabling Follow Up; Precautions - Mitsubishi Electric MELSEC iQ-R Series User Manual

Disabling follow up

The follow up enabled/disabled can be switched for each axis (default status: enabled). Input from the slave device (the
current position) is disabled and not reflected in the set position by switching the follow up to enabled.
That the follow up enabled/disabled is switched is recorded in the event history. Also, for the real drive axis,
the servo ON from the follow up disabled status during the servo OFF is recorded in the event history as well.
At this time, the difference [driver-based] between the drive unit target position (Target position) and the
current position (Position actual value) is also recorded in the event history.
For real drive axis
AxisName.Md.FollowupDisable turns TRUE by changing AxisName.Cd.FollowupDisable to TRUE, and the follow up is
disabled.
AxisName.Md.
Driver_ServoON
AxisName.Cd.
FollowupDisable
AxisName.Md.
FollowupDisable
Current position
*1
of drive unit
AxisName.Md.
*2
SetPosition
Follow up

Precautions

[Only for real drive axes]
• When the follow up is enabled after the current position of the drive unit is moved while the follow up is disabled, the motion
system reflects the distance from the drive unit in the set position within one operation cycle. Therefore, when a single axis
synchronous control is executed using an applicable axis as the master axis, the command of the movement amount of the
set position is transmitted to the slave axis.
• The motion system outputs the distance to the drive unit within one operation cycle for the following cases. Note that a rapid
operation may occur in the drive unit.
When the servo ON occurs next time after the current position of the drive unit is moved in the follow up disabled status
during the servo OFF
When the system stopped in the servo ON status after the control excluding the position loop, such as the speed control,
was executed with the follow up disabled status
• The software stroke limit function is invalid during the servo OFF. Therefore, set the software stroke limit in the slave axis or
the following axis for safety in order to transmit the command under follow up in the single axis synchronous control to the
slave axis.
executed
MC_MoveVelocity executed
Request applied from
the start of follow up.
Instruct the drive unit to move
to the set position.
The move of the drive unit during
invalid of follow up is applied to
the set position.
*1 When checking with slave label
*2 When driver unit conversion (Numerator / Denominator) is (1 / 1).
2 AXIS MANAGEMENT FUNCTIONS
2
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2.5 Follow Up