Mitsubishi Electric MELSEC-L LD75D, User Manual

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406
(5) 3-axis helical interpolation control with sub point designation (INC helical sub)
(a) Operation chart
In this control, positioning is carried out from the current stop position (X0, Y0, Z0) to the movement amount
position (X1, Y1, Z1) set in "[Da.6] Positioning address/movement amount". Circular interpolation where the arc
path passes through the address of the sub point (sub point address) set in "[Da.7] Arc address" is carried out.
Simultaneously, linear interpolation is carried out with the other linear axis. The control path is helically rotated
for the number of pitch set in "[Da.10] M code" of the linear axis to complete the positioning to the specified
position. The movement direction is determined by the sign of the movement amount.
The resulting control path is an arc having its center as 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).
(b) Restrictions
3-axis helical interpolation control cannot be set in the following cases.
• When "degree" is set in "[Pr.1] Unit setting" for 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. ("mm" and "inch" combinations are possible.)
• When a method other than "composite speed" is set in "[Pr.20] Interpolation speed designation method" or
"[Da.29] Interpolation speed designation method"
An error will occur and the positioning will not start in the following cases. The machine will immediately stop if
the error is detected during positioning control.
Operation chart Circular interpolation plane
Error cause Error code
When the radius exceeds "536870912 (= 2
29
)". (The maximum radius for
which circular interpolation control is possible is "536870912 (= 2
29
)".)
An error "Outside radius range" (error code: 544) will occur at positioning start.
Sub point address is outside the range of

2147483648 (

2
31
) to 2147483647
(2
31

1).
An error "Sub point setting error" (error code: 525) will occur at positioning
start.
End point address is outside the range of

2147483648 (

2
31
) to 2147483647
(2
31

1).
An error "End point setting error" (error code: 526) will occur at positioning
start.
Center point address is outside the range of

2147483648 (

2
31
) to
2147483647 (2
31

1).
An error "Sub point setting error" (error code: 525) will occur at positioning
start.
Start point address = End point address Error "End point setting error" (error code: 526)
Start point address = Sub point address Error "Sub point setting error" (error code: 525)
End point address = Sub point address Error "Sub point setting error" (error code: 525)
When the start point address, end point address, and sub point address are in
a straight line
Error "Sub point setting error" (error code: 525)
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)
Arc sub point
Circular interpolation control
end point (X1, Y1)
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