Mitsubishi Electric RD77MS2 User Manual page 90

2-axis circular interpolation control with sub point designation (INC circular sub)
■Operation chart
In the incremental system, 2-axis circular interpolation control with sub point designation, positioning is carried out from the
current stop position (start point address) to a position at the end of the movement amount 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 movement
direction depends on the sign (+ or -) of the movement amount.
The resulting control path is an arc having as its center the intersection point of perpendicular bisectors of the straight line
between the start point address (current stop position) and sub point address (arc address) calculated from the movement
amount to the sub point, and a straight line between the sub point address (arc address) and end point address (positioning
address) calculated from the movement amount to the end point.
Forward direction
Movement
amount
to sub point
Reverse direction
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 sub point address is outside the range of "-2147483648 (-2
setting error" (error code: 1A27H to 1A2AH) will occur.
• When the end point address is outside the range of "-2147483648 (-2
setting error" (error code: 1A2BH, 1A2CH) will occur.
• 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
88
3.2 Setting the Positioning Data
Sub point address
(arc address)
Start point
address
Movement
amount
to sub point
Movement amount to the end point
29
)"): The error "Outside radius range" (error code: 1A32H) will occur at positioning start.
Movement by circular interpolation
Arc
center
Forward direction
)" (the maximum radius for which circular interpolation control is possible is
31
31
Movement amount
to the end point
31
) to 2147483647 (2 - 1)": The error "Sub point
31
) to 2147483647 (2 - 1)": The error "End point
31 31
) to 2147483647 (2 - 1)": The error "Sub point