Mitsubishi Electric RD77MS2 - Page 101

3 MAJOR POSITIONING CONTROL
3.2 Setting the Positioning Data
99
3
3-axis helical interpolation control with sub point designation (INC helical sub)
■Operation chart
In the incremental system and 3-axis helical interpolation control with sub point designation, the positioning is performed from
the current stop position (X0, Y0, Z0) to the position (X1, Y1, Z1) for the movement amount set in "[Da.6] Positioning address/
movement amount". As the positioning to the commanded position, the linear interpolation with the other linear interpolation
axes is performed and the positioning target is rotated helically for the number of pitches set in "[Da.10] M code/Condition
data No./Number of LOOP to LEND repetitions/Number of pitches" of the linear interpolation axis while the circular
interpolation through the sub point address (sub point address) set in "[Da.7] Arc address" is performed. The movement
direction is determined by the sign of the movement amount.
The resulting path is an arc whose center is the intersection point of the perpendicular bisectors of a straight line between the
start point address (current stop position) and the 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 the end point address (positioning address)
calculated from the movement amount to the end point.
■Restrictions
In the following cases, the 3-axis helical interpolation control cannot be set.
• When "degree" is set in "[Pr.1] Unit setting" of the reference axis and circular interpolation axis
• When the units set in "[Pr.1] Unit setting" are different between the reference axis and circular interpolation axis (The
combination of "mm" and "inch" is possible.)
• When "reference axis speed" is set in "[Pr.20] Interpolation speed designation method"
• When the value out of the range of "0 to 999" is set in the number of pitches ("[Da.10] M code/Condition data No./Number
of LOOP to LEND repetitions/Number of pitches")
In the following case, an error occurs and the positioning will not start. During the positioning control, the operation stops
immediately at the detection of the error.
Operation chart Top view of the circular interpolation
Error cause Error code
When the radius exceeds 536870912 (= 2
29
) (The maximum radius for which
the circular interpolation control is possible is 536870912 (= 2
29
).)
The error "Outside radius range" (error code: 1A32H) occurs at the start of the
positioning.
When the sub point address is out of the range of -2147483648 (-2
31
) to
2147483647 (2
31
-1)
The error "Sub point setting error" (error code: 1A2AH) occurs at the start of
the positioning.
When the end point address is out of the range of -2147483648 (-2
31
) to
2147483647 (2
31
-1)
The error "End point setting error" (error code: 1A2CH) occurs at the start of
the positioning.
When the center point address is out of the range of -2147483648 (-2
31
) to
2147483647 (2
31
-1)
The error "Sub point setting error" (error code: 1A37H) occurs at the start of
the positioning.
Start point address = End point address The error "End point setting error" (error code: 1A2BH)
Start point address = Sub point address The error "Sub point setting error" (error code: 1A27H)
End point address = Sub point address The error "Sub point setting error" (error code: 1A28H)
When the start point address, sub point address, and end point address are
on a straight line
The error "Sub point setting error" (error code: 1A29H)
Linear
movement
amount
Z axis
Y axis
X axis
Arc sub point
Circular interpolation control
end point (X1, Y1)
Linear control end point (Z1)
Number of pitch
Circular interpolation control
start point (X0, Y0)
Linear control start point (Z0)
Circular interpolation control
end point (X1, Y1)
Arc sub point
Center point
Circular interpolation control
start point (X0, Y0)
Movement
amount
to the sub point
Movement amount
to the sub point
Movement
amount
to the
end point