IAI America XSEL-QX - Manual (Page 284)

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Part 4 Commands
z ARC (Move along arc in CP operation)
Command, declaration
Extension condition
(LD, A, O, AB, OB)
Input condition
(I/O, flag)
Command,
declaration
Operand 1 Operand 2
Output
(Output, flag)
Optional Optional ARC
Passing
position
number
End position
number
PE
[Function] Move along an arc from the current position to the position specified in operand 2, by passing
the position specified in operand 1.
The output will turn OFF at the start of arc movement, and turn ON when the movement is
complete.
Difference from ARC2:
ARC processing resembles moving along a polygon with a PATH command, while ARC2
actually performs arc interpolation.
Select an applicable command by considering the characteristics of each command.
(Normally ARC2 is used.)
(Note 1) Movement to any position where target values for both SCARA and linear movement axes are
specified simultaneously is prohibited (“Error No. 421, SCARA/linear movement axis
simultaneous specification error”).
To perform any operation meeting the above condition, use a GRP command or set different
position data for SCARA axes and for linear movement axes.
(Note 2) If the division angle is set to “0” with a DEG command (division angle is calculated automatically
based on priority speed setting), the speed set in the data at passing position 1 or speed set by
a VEL command will be used (former is given priority). The speed set in the data at passing
position 2 will have no meaning.
(Note 3) If the division angle is set to a value other than “0” with a DEG command (normal division
angle), the speed specified in the target position data will be used. (The speed set by a VEL
command will become valid if position data is not specified.)
(Note 4) The acceleration is selected in the order of the acceleration in the data at passing position 1,
followed by the value set in an ACC command, and the value in “All-axis parameter No. 11,
Default acceleration of SCARA axis” or “All-axis parameter No. 200, Default acceleration of
linear movement axis.”
The deceleration will become the same value as the valid acceleration selected above.
Therefore, the deceleration in the data at passing position 1 and the acceleration/deceleration in
the data at passing position 2 will not have any meaning.
(Note 5) This command is valid on arbitrary cartesian planes. (Depending on the position data, axis 2
may be selected automatically and preferentially before axis 1.)
(Note 6) If the interval between the position origin and passing position or between the passing position
and end position is small and the locus passes near a soft limit, an “Error No. C73, Target-locus
soft limit over error” may generate.
If the interval between the position origin and passing position 1 or between passing position 1
and passing position 2 is small and the locus passes near a soft limit, an “Error No. C73, Target-
locus soft limit over error” may generate. In this case, take an appropriate action such as
increasing the position intervals as much as possible or setting the locus slightly inward of the
soft limit boundary.
[Example 1] VEL 100 Set the speed to 100 mm/s.
ARC 100 101 Move along an arc from the current position to position 101
by passing position 100.
[Example 2] VEL 100 Set the speed to 100 mm/s.
LET 1 5 Assign 5 to variable 1.
LET 2 6 Assign 6 to variable 2.
ARC *1 *2 Move along an arc from the current position to the content
of variable 2 (position 6) by passing the content of variable
1 (position 5).