12 - 50
MELSEC-A
12 CONTROL AUXILIARY FUNCTIONS
12.5.2 Override function
The override function changes the command speed by a designated percentage (1 to
300%) for all control to be executed.
The speed can be changed by setting the percentage (%) by which the speed is
changed in "
Cd.18 Positioning operation speed override".
(1) Control details
(2) Precautions during control
(3) Setting the override function
(1) Control details
The following shows that operation of the override function.
1) A value changed by the override function is monitored by "
Md.31
Feedrate".
2) If "
Cd.18 Positioning operation speed override" is set to 100%, the speed
will not change.
3) If "
Cd.18 Positioning operation speed override" is set a value less than
100%, control will be carried out at speed unit "1" at the time "
Md.31
Feedrate" becomes a value of "1" or less.
4) If there is not enough remaining distance to change the speed when the
speed is changed during the position control of speed/position changeover
control, the operation will be carried out at the speed that could be changed.
5) If the speed changed by the "override function" is greater than the "
Pr.7
Speed limit value", a warning "speed limit value over" (warning code: 501)
will occur and the speed will be controlled at the "
Pr.7 Speed limit value".
The "
Md.49
In speed limit flag" will turn ON.
Cd. 18
Da. 7 Command speed
Md. 31 Feedrate
100
1
50 150
100
200
50
50 1 25
75
50 75
Not affected by the override value
during deceleration
Not enough remaining
distance could be secured
so operation is carried out
at an increased speed.
t
V
Positioning operation
speed override value
Fig. 12.27 Override function operation
To Next Page
Loading...
