Position-Speed Switching Control - Mitsubishi Electric MELSEC-L LD75P User Manual

9.2.20

Position-speed switching control

In "position-speed switching control" ("[Da.2] Control system" = Forward run: position/speed, Reverse run:
position/speed), before the position-speed switching signal is input, position control is carried out for the movement
amount set in "[Da.6] Positioning address/movement amount" in the axis direction in which the positioning data has
been set. When the position-speed switching signal is input, the position control is carried out by continuously
outputting the pulses for the speed set in "[Da.8] Command speed" until the input of a stop command.
The two types of position-speed switching control are "Forward run: position/speed" in which the control starts in the
forward run direction, and "Reverse run: position/speed" in which control starts in the reverse run direction.
(1) Switching over from position control to speed control
• The control is switched over from position control to speed control by executing the external command signal
set in "position-speed switching signal".
• Besides setting the positioning data, the "[Cd.26] Position-speed switching enable flag" must also be turned
ON to switch over from position control to speed control. (If the "[Cd.26] Position-speed switching enable
flag" turns ON after the position-speed switching signal turns ON, the control will continue as position control
without switching over to speed control. The control will be switched over from position control to speed
control when the position-speed switching signal turns from OFF to ON again. Only speed control will be
carried out when the "[Cd.26] Position-speed switching enable flag" and position-speed switching signal are
ON at the operation start.)
Setting item
Position-speed switching
[Cd.26]
enable flag
(2) Position-speed switching signal setting
The following table shows the items that must be set to use the external command signals (CHG) as position-
speed switching signals.
Setting item
External command function
[Pr.42]
selection
[Cd.8] External command valid
Refer to  Page 118, Section 5.2 and Page 211, Section 5.7 for the information on detail settings.
Setting
Setting details
value
Set also "1: Switch from position control to
1 speed control when the external command
signal [CHG] turns ON.".
Setting
Setting details
value
Set the "2: speed-position and position-
2
speed switching requests".
1 Set "1: Validate external command".
CHAPTER 9 MAJOR POSITIONING CONTROL
Buffer memory address
Axis 1 Axis 2 Axis 3
1532 1632 1732
Buffer memory address
Axis 1 Axis 2 Axis 3
62 212 362
1505 1605 1705
9
Axis 4
1832
Axis 4
512
1805
441