Mitsubishi Electric MELDAS MDS-R Series Technical Specification And Instruction Manual page 166

(4) Adjusting for feed forward control
In LMC compensation, a model position considering the position loop gain is calculated based on
the position command sent from the CNC, and compensation is carried out when the feed changes
to that direction. When the CNC carries out feed forward (fwd) control, overshooting equivalent to
the operation fraction unit occurs in the position commands, and the timing of the model position
direction change may be mistaken. As a result, the LMC compensation timing may deviate, or
compensation may be carried out twice or more.
If feed forward control is carried out and the compensation does not operate correctly, Lost motion
compensation non-sensitive band (SV040 (LMCT)) during feed forward control. In this
non-sensitive band control, overshooting of the set width or less is ignored. The model position
direction change point is correctly recognized, and the LMC compensation is correctly executed.
This parameter is meaningless when feed forward control is not being carried out.
<Adjustment method>
If the compensation timing deviates during feed forward control, increase the LMCT setting by 1µm
at a time.
Note that 2µm are set even when the LMCT is set to 0.
No. Abbrev. Parameter name
SV040 LMCT Lost motion
compensation
non-sensitive band
9. Adjustment
Set the non-sensitive band of the lost motion compensation in the feed
forward control.
When "0" is set, the actual value that is set is 2µm. Adjust by increasing
by 1µm at a time.
9 - 22
Explanation Setting range
0 to 100
(µm)