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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  :  The error "Interpolation while interpolation axis BUSY" 
(error code: 519) 
 
 Interpolation axis  :  The error "Control system setting error" (error code: 524), 
The warning "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 number of the interpolation axes and axes to be interpolated cannot be 
changed from the intermediate positioning data. An error "Control system setting 
error" (error code: 524) will occur and the positioning will stop if setting, which 
changes the number of the interpolation axes and axes to be interpolated, is 
carried out. 
 
 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 error "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.