Mitsubishi Electric MELSEC Q Series, User Manual

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Chapter 9 Major Positioning Control
POINTS

When the movement amount is converted to the actual number of command
pulses, a fraction appears after the decimal point, according to the movement
amount per pulse. This fraction is normally retained in the Simple Motion module
and reflected at the next positioning.
For the fixed-feed control, since the movement distance is maintained constant (=
the command number of pulses is maintained constant), the control is carried out
after the fraction pulse is cleared to zero at start.
[Accumulation/cutoff for fractional pulses]
When movement amount per pulse is 1.0 [

m] and movement for 2.5 [

m] is
executed two times.

Conversion to command pulses: 2.5 [

m] ÷ 1.0 = 2.5 [PLS]
0.5 PLS hold by the Simple Motion
module is cleared to 0 at start and
not carried to next positioning.
2PLS
2PLS 2PLS
3PLS(=2.5+0.5)
Movement
amount
INC Linear 1
Fixed-feed 1
2.5 m 2.5 m
0.5 PLS hold by the Simple Motion
module is carried to next positioning.
 When the "reference axis speed" is set during 4-axis fixed-feed control, set so the
major axis side becomes the reference axis. If the minor axis side is set as the
reference axis, the major axis side speed may exceed the "[Pr.8] Speed limit
value".
 Refer to Section 9.1.6 "Interpolation control" for the reference axis and
interpolation axis combinations.