Yaskawa LEGEND-MC - Manual (Page 274)

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LEGEND-MC User’s Manual
Linear Interpolation Mode
The LEGEND-MC provides a linear interpolation mode for 1 axis. In linear interpolation mode, motion is
coordinated to maintain the prescribed vector speed, acceleration, and deceleration along the specified
path. The motion path is described in terms of incremental distances. An unlimited number of incremental
segments may be given in a continuous move sequence, making the linear interpolation mode ideal for
following a piece-wise linear path. There is no limit to the total move length.
The LM command selects the Linear Interpolation mode and axes for interpolation. For example, LM X
selects the X axis for linear interpolation.
When using the linear interpolation mode, the LM command only needs to be specified once unless the
axes for linear interpolation change.
Specifying Linear Segments
The command LI x specifies the incremental move distance for each axis. This means motion is prescribed
with respect to the current axis position. Up to 511 incremental move segments may be given prior to the
Begin Sequence (BGS) command. Once motion has begun, additional LI segments may be sent to the
controller.
The clear sequence (CS) command can be used to remove LI segments stored in the buffer prior to the
start of the motion. To stop the motion, use the instructions STS or AB. The command, ST, causes a
decelerated stop. The command, AB, causes an instantaneous stop and aborts the program, and the
command AB1 aborts the motion only.
The Linear End (LE) command must be used to specify the end of a linear move sequence. This command
tells the controller to decelerate to a stop following the last LI command. If an LE command is not given,
an Abort AB1 must be used to abort the motion sequence.
It is the responsibility of the user to keep enough LI segments in the LEGEND-MC sequence buffer to
ensure continuous motion. If the controller receives no additional LI segments and no LE command, the
controller will stop motion instantly at the last vector. There will be no controlled deceleration. LM? or
_LM returns the available spaces for LI segments that can be sent to the buffer. 511 returned means the
buffer is empty and 511 LI segments can be sent. A zero means the buffer is full and no additional
segments can be sent. As long as the buffer is not full, additional LI segments can be sent.
The instruction _CS returns the number of the segment being processed. As the segments are processed,
_CS increases, starting at zero. This function allows the host computer to determine which segment is
being completed.
Additional Commands
The commands VS n, VA n, and VD n are used to specify the vector speed, acceleration, and deceleration.
The LEGEND-MC computes the vector speed based on the axes specified in the LM mode. For example,
VT is used to set the S-curve smoothing constant for coordinated moves. The command AV n is the ‘After
Vector’ trippoint, which halts program execution until the vector distance of n has been reached.