Mitsubishi Electric Q172CPU Programming Manual page 348

7 MOTION PROGRAMS FOR POSITIONING CONTROL
[Related Parameters]
[Program Example]
(7) When the control unit is [degree], operation from the mid point to the home
position differs between the absolute value command (G90) and incremental
value command (G91).
The axis travels in the nearest path under the absolute value command (G90), or
in the direction specified in the home position return direction parameter under the
incremental value command (G91).
(8) The following parameter blocks are used at the home position return (G28).
(a) Home position return request ON
(b) Home position return request OFF
Home position address : The current value of the home position is set.
High-speed feed rate
The program which executes the home position return from the current position
through the A point (mid point).
G90 ;
G28 X200. Y200. ; (Home position return)
A point (mid point coordinates X200, Y200)
Current position
REMARK
When the G28 is commanded, a home position return is made at the high-speed
feed rate.
.....
....
(Refer to Section 8.5.1 Home position return data.)
: The high-speed feed rate of each axis is set.
(Refer to Section 6.2.5 High-speed feed rate setting.)
Home position
Home position return request signal (M2409+20n) is ON
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Parameter block specified with home
position return parameter.
Parameter block at the axis specified
program start.