Mitsubishi Electric QD77MS User Manual page 750

[2] Precautions during operation
(1) If the positioning movement direction from the stop position to a new target
position is reversed, stop the operation once and then position to the new
target position. (Refer to Fig. 13.31 (c).)
(2) If a command speed exceeding the speed limit value is set to change the
command speed, the warning "Speed limit value over" (warning code: 501)
will occur and the new command speed will be the speed limit value.
Also, if the command speed change disables the remaining distance to the
target value from being assured, the warning "Insufficient remaining
distance" will occur (warning code: 509).
(3) In the following cases, a target position change request given is ignored and
the warning "Target position change not possible" (warning code: 518)
occurs.

During interpolation control
 A new target position value (address) is outside the software stroke limit
range.

The axis is decelerating to a stop by a stop cause.
 While the positioning data whose operation pattern is continuous path
control is executed.
 When the speed change 0 flag ([Md.31] Status: b10) is ON.
(4) When a command speed is changed, the current speed is also changed.
When the next positioning speed uses the current speed in the continuous
positioning, the next positioning operation is carried out at the new speed
value. When the speed is set with the next positioning data, the speed
becomes the current speed and the operation is carried out at the current
speed.
(5) When a target position change request is given during automatic deceleration
in position control, positioning control to a new position is exercised after the
axis has stopped once if the moving direction is reversed. If the moving
direction is not reversed, the axis is accelerated to the command speed again
and positioned to the new position.
(6) If the constant speed status is regained or the output is reversed by a target
position change made while "[Md.48] Deceleration start flag" is ON, the
deceleration start flag remains ON. (For details, refer to Section 13.7.8.)
(7) Carrying out the target position change to the ABS linear 1 in degrees may
carry out the positioning to the new target position after the operation
decelerates to stop once, even the movement direction is not reversed.
POINT
When carrying out the target position change continuously, take an interval of 100
ms or longer between the times of the target position changes. Also, take an
interval of 100 ms or longer when the speed change and override is carried out
after changing the target position or the target position change is carried out after
the speed change and override.
13 - 62
Chapter 13 Control Sub Functions