Mitsubishi Electric MELSEC Q Series, User Manual

Page: 471 / 834

9 - 71
Chapter 9 Major Positioning Control
In circular interpolation control with center point designation, an angular velocity is
calculated on the assumption that operation is carried out at a command speed on
the arc using the radius calculated from the start point address and center point
address, and the radius is compensated in proportion to the angular velocity
deviated from that at the start point.
Thus, when there is a difference (error) between a radius calculated from the start
point address and center point address (start point radius) and a radius calculated
from the end point address and center point address (end point radius), the
composite speed differs from the command speed as follows.
Start point radius > End point radius: As compared with the speed without error,
the speed becomes slower as end point
address is reached.
Start point radius < End point radius: As compared with the speed without error,
the speed becomes faster as end point
address is reached.
Restrictions
(1) 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"
(2) 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
)". (The maximum radius for
which circular interpolation control is possible is "536870912 (=2
29
)")
... The error "Outside radius range" (error code: 544) will occur at
positioning start.

When the end point address is outside the range of –2147483648 (-2
31
) to
2147483647 (2
31
-1)
... The error "End point setting error" (error code: 526) will occur.
 When the start point address is the same as the center point address
... The error "Center point setting error" (error code: 527) will occur.
 When the end point address is the same as the center point address
... The error "Center point setting error" (error code: 527) will occur.
 When the center point address is outside the range of –2147483648 (-2
31
) to
2147483647 (2
31
-1)
... The error "Center point setting error" (error code: 527) will occur.