
B--63003EN--1/02
15. PMC CONTROL FUNCTION
1213
When using the speed command (EC0g to EC6g: 10h), specify the axis
to be controlled as a rotation axis in ROTX, bit 0 of parameter No. 1006.
While position control is being executed for the continuous feed
command (EC0g to EC6g: 06h), the speed command (EC0g to EC6g:
10h) exerts speed control over the servo motor, thus allowing the speed
to be dynamically changed during continuous feed. This makes this
command suitable for driving a rotation tool with a servo motor.
A linear acceleration/deceleration time constant can be set for each axis,
using parameter No. 8028.
Note that, while jog feed is being executed by the speed command, no
coordinate system values are changed. This will result in the loss of the
tool position. Therefore, after continuous feed has been completed,
always return the tool to the reference position before executing the move
command.
The machine coordinate system selection command (EC0g to EC6g:
20h) performs absolute positioning to move the tool in rapid traverse to
a specified position on the machine coordinate system. This command
is used to move the tool to a position specifically defined for the machine,
such as the tool exchange position.
This command can be used, irrespective of whether the optional function
for workpiece coordinate system setting is provided.
For a rotation axis, short cut rotation can also be specified. When using
this command for the T series, cancel the tool offset and the tool nose
radius compensation. For the M series, cancel cutter compensation, tool
length compensation, and tool offset.
The machine coordinate system must be set before attempting to use this
command. After turning on the power, return the tool to the reference
position either manually or by using G28. When an absolute position
detector is provided, returning the tool to the reference position is not
necessary because the tool position will be stored in memory.
When torque control is selected (EC0g to EC6g: 11h), the PMC
controlled axis can be subjected to torque control instead of position
control. In the torque control mode, the servo motor outputs the torque
specified by the NC.
(1)Switching from position control to torque control
a. Setting a torque control axis
Set the axis to be subjected to torque control in the TRQMx bit (bit
7 of parameter No. 2007). Set the torque control axis also in
parameter No. 2105 of torque constant. The motor--specific
standard value is automatically set in this parameter when the
power is turned on with the DGPR bit (bit 1 of parameter No. 2000)
set to 0.
b. Position management in torque control mode
In torque control mode, whether to perform follow--up can be
selected by setting the TQF bit (bit 4 of parameter No. 1803).
Speed command
Machine coordinate
system selection
Torque control command