Melsec-q, 9 major positioning control – MITSUBISHI ELECTRIC Mitsubishi Programmable Logic Controller QD75D User Manual

Page 323

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MELSEC-Q

9 MAJOR POSITIONING CONTROL

Starting the interpolation control

The positioning data Nos. of the reference axis (axis in which interpolation control

was set in " Da.2 Control system") are started when starting the interpolation

control. (Starting of the interpolation axis is not required.)
The following errors or warnings will occur and the positioning will not start if both
reference axis and the interpolation axis are started.

Reference axis

: Interpolation while interpolation axis BUSY (error code:

519)

Interpolation axis : Control system setting error (error code: 524), start during

operation (warning code: 100).

Interpolation control continuous positioning

When carrying out interpolation control in which "continuous positioning control"
and "continuous path control" are designated in the operation pattern, the
positioning method for all positioning data from the started positioning data to the
positioning data in which "positioning complete" is set must be set to interpolation
control.
The QD75 may malfunction if a control system other than interpolation control is
set.

Speed during interpolation control

Either the "composite speed" or "reference axis speed" can be designated as the
speed during interpolation control.

(

Pr.20

Interpolation speed designation method)

Only the "Reference axis speed" can be designated in the following interpolation
control.
When a "composite speed" is set and positioning is started, the "Interpolation
mode error (error code: 523)" occurs, and the system will not start.
• 4-axis linear interpolation
• 2-axis speed control
• 3-axis speed control
• 4-axis speed control

Cautions in interpolation control

(1) If a stepping motor is used, the circular interpolation control cannot be carried

out.
Ensure to use a servomotor when the circular interpolation control is carried
out.

(2) If either of the axes exceeds the " Pr.8 Speed limit value" in the 2 to 4 axes

speed control, the axis which exceeded the speed limit value is controlled by
the speed limit value.
For the other axes which perform interpolation, the speed can be suppressed
by the ratio of a command speed.

If the reference axis exceeds " Pr.8 Speed limit value" during 2- to 4-axis

linear interpolation control, 2- to 4-axis fixed-feed control or 2-axis circular
interpolation control, the reference axis is controlled at the speed limit value.
(The speed limit does not function on the interpolation axis side.)

(3) In 2-axis interpolation, you cannot change the combination of interpolated axes

midway through operation.

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