2-Axis Circular Interpolation Control With Sub Point Designation - Mitsubishi Electric RD77MS2 User Manual

2-axis circular interpolation control with sub point designation

In "2-axis circular interpolation control" ("[Da.2] Control method" = ABS circular sub, INC circular sub), two motors are used to
carry out position control in an arc path passing through designated sub points, while carrying out interpolation for the axis
directions set in each axis. (Refer to Page 64 Interpolation control for details on interpolation control.)
2-axis circular interpolation control with sub point designation (ABS circular sub)
■Operation chart
In the absolute system, 2-axis circular interpolation control with sub point designation, positioning is carried out from the
current stop position (start point address) to the address (end point address) set in "[Da.6] Positioning address/movement
amount", in an arc path that passes through the sub point address set in "[Da.7] Arc address".
The resulting control path is an arc having as its center the intersection point of perpendicular bisectors of a straight line
between the start point address (current stop position) and sub point address (arc address), and a straight line between the
sub point address (arc address) and end point address (positioning address).
Forward direction
Reverse direction
Home position
Reverse direction
■Restrictions
2-axis circular interpolation control cannot be set in the following cases.
• When "degree" is set in "[Pr.1] Unit setting"
• When the units set in "[Pr.1] Unit setting" are different for the reference axis and interpolation axis. ("mm" and "inch"
combinations are possible.)
• When "reference axis speed" is set in "[Pr.20] Interpolation speed designation method"
An error will occur and the positioning start will not be possible in the following cases. The machine will immediately stop if the
error is detected during positioning control.
• When the radius exceeds "536870912 (= 2
29
"536870912 (= 2
• When the center point address is outside the range of "-2147483648 (-2
setting error" (error code: 1A27H to 1A2AH) will occur at positioning start.
• When the start point address is the same as the end point address: The error "End point setting error" (error code: 1A2BH,
1A2CH) will occur.
• When the start point address is the same as the sub point address: The error "Sub point setting error" (error code: 1A27H
to 1A2AH) will occur.
• When the end point address is the same as the sub point address: The error "Sub point setting error" (error code: 1A27H to
1A2AH) will occur.
• When the start point address, sub point address, and end point address are in a straight line: The error "Sub point setting
error" (error code: 1A27H to 1A2AH) will occur.
3 MAJOR POSITIONING CONTROL
86
3.2 Setting the Positioning Data
Movement by circular interpolation
Sub point address
(arc address)
Start point address
(current stop position)
29
)"): The error "Outside radius range" (error code: 1A32H) will occur at positioning start.
End point address
(positioning address)
Arc center point
Forward direction
)" (the maximum radius for which circular interpolation control is possible is
31 31
) to 2147483647 (2 - 1)": The error "Sub point