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MELSEC-Q
12 CONTROL SUB FUNCTIONS
[2] Control precautions
(1) When changing the speed by the "override function" during continuous path
control, the speed change will be ignored if there is not enough distance
remaining to carry out the change.
(2) A warning "Deceleration/stop speed change" (warning code: 500) occurs
and the speed cannot be changed by the "override function" in the following
cases.
(The value set in "
Cd.13
Positioning operation speed override" is validated
after a deceleration stop.)
•
During deceleration by a stop command
•
During automatic deceleration during positioning control
(3) When the speed is changed by the "override function" during interpolation
control, the required speed is set in the reference axis.
(4) When carrying out consecutive speed changes by the "override function", be
sure there is an interval between the speed changes of 100ms or more.
(If the interval between speed changes is short, the QD75 will not be able to
track, and it may become impossible to carry out commands correctly.)
(5) When a machine OPR is performed, the speed change by the "override
function" cannot be carried out after a deceleration start to the creep speed
following the detection of near-point dog ON. In this case, a request for
speed change is ignored.
(6) When deceleration is started by the override function, the deceleration start
flag does not turn ON.
[3] Setting method
The following shows the data settings and sequence program example for setting
the override value of axis 1 to "200%".
(1) Set the following data. (Use the start time chart shown in section (2) below
as a reference, and set using the sequence program shown in section (3).)
Buffer memory address
Setting item
Setting
value
Setting details
Axis
1
Axis
2
Axis
3
Axis
4
Cd.13
Positioning
operation speed
override
200 Set the new speed as a percentage (%). 1513 1613 1713 1813
Refer to Section 5.7 "List of control data" for details on the setting details.
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