Mitsubishi Electric MELSEC-Q Series - Page 353

6 - 166
6 POSITIONING CONTROL
POINTS
(1) The fixed acceleration/deceleration time method is acceleration/deceleration processing
that the time which acceleration/deceleration takes is fixed, even if the command speed
differs.
A
cceleration/deceleration time is fixed
V
t
(a) The following processing and parameters are invalid in the fixed
acceleration/deceleration time method.
• Rapid stop deceleration time in parameter block
• Completion point specification method for speed change point
• S-curve acceleration/deceleration
(b) The speed processing for each axis is as shown below in positioning operation
(constant-speed) as shown in the following figure.
Y
Axis 1
Axis 2
Address Ax
Positioning operation
X
Ax
Ay
Address A
y
t
V
V
Axis 1
Axis 2
Ay
t
Constant-speed control processing of each axis
Ax
(2) When the rapid stop command is executed by the setting "deceleration time < rapid stop
deceleration time" during constant-speed control, the point data currently executed in the
middle of deceleration, and the positioning may be completed suddenly as a speed "0".
In the case of, "deceleration time  rapid stop deceleration time", the above operation is
not executed
. For the following condition, note that the speed may become 0 in the middle of
deceleration.
Travel value by the point data currently executed at the rapid stop command
(Up to 9 points) < speed at rapid stop command input
rapid stop deceleration time/2
[Operation pattern]
Positioning complete
signal
Rapid stop command
Deceleration speed at
the normal stop
Vector speed
OFF
ON
OFF
OFF
ON
Start accept flag
8)7)6)5)4)3)2)1)
ON