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Vector Mode: Linear and Circular Interpolation Motion
The DMC-21x5 allows a long 2-D path consisting of linear and arc segments to be prescribed. Motion along the
path is continuous at the prescribed vector speed even at transitions between linear and circular segments. The
DMC-21x5 performs all the complex computations of linear and circular interpolation, freeing the host PC from this
time intensive task.
The coordinated motion mode is similar to the linear interpolation mode. Any pair of two axes may be selected for
coordinated motion consisting of linear and circular segments. In addition, a third axis can be controlled such that
it remains tangent to the motion of the selected pair of axes. Note that only one pair of axes can be specified for
coordinated motion at any given time.
The command
VM
mnp
Specifying the Coordinate Plane
The DMC-21x5 allows for 2 separate sets of coordinate axes for linear interpolation mode or vector mode. These
two sets are identified by the letters S and T.
To specify vector commands the coordinate plane must first be identified. This is done by issuing the command
to identify the S plane or
CAS
coordinate system until changed with the
Specifying Vector Segments
The motion segments are described by two commands;
a set of linear segments and/or circular segments have been specified, the sequence is ended with the command
VE. This defines a sequence of commands for coordinated motion. Immediately prior to the execution of the first
coordinated movement, the controller defines the current position to be zero for all movements in a sequence.
Note: This local definition of zero does not affect the absolute coordinate system or subsequent coordinated
motion sequences.
The
command specifies the coordinates of the end points of the vector movement with respect to the starting
VP
point. Non-sequential axis do not require comma delimitation. The
radius, starting angle, and a traversed angle. The notation for a starting angle of zero corresponds to the positive
horizontal direction, and a positive traverse angle corresponds to the counter-clockwise (CCW) direction.
Up to 511 segments of
The motion can be initiated with a Begin Sequence (BGS) command. Once motion starts, additional segments may
be added.
The Clear Sequence (CS) command can be used to remove previous
the buffer prior to the start of the motion. To stop the motion, use the instructions
the specified deceleration.
The Vector End (VE) command must be used to specify the end of the coordinated motion. This command requires
the controller to decelerate to a stop following the last motion requirement. If a
Abort (AB1) must be used to abort the coordinated motion sequence.
It is the responsibility of the user to keep enough motion segments in the DMC-21x5 sequence buffer to ensure
continuous motion. If the controller receives no additional motion segments and no
will stop motion instantly at the last vector. There will be no controlled deceleration.
spaces for motion segments that can be sent to the buffer. 511 returned means the buffer is empty and 511
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 segments can be sent at PC bus speeds.
The operand
_CS
can be used to determine the value of the segment counter.
Chapter 6 Programming Motion ▫ 49
where m and n are the coordinated pair of axes and p is the tangent axis
to identify the T plane. All vector commands will be applied to the active
CAT
command.
CA
or
may be specified in a single sequence and must be ended with the command VE.
CR
VP
aborts the motion instantaneously.
AB1
VP
for linear segments and
command defines a circular arc with a
CR
and
commands which were stored in
VP
CR
VE
CR
for circular segments. Once
or AB1.
stops motion at
STS
ST
command is not given, an
command, the controller
VE
returns the available
_LM
DMC-21x5 User Manual 1.0a1
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