Specifying Vector Segments; Additional Commands - Galil Motion Control DMC-1600 Series User Manual

Specifying Vector Segments

The motion segments are described by two commands; VP for linear segments and CR for circular
segments. Once 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 VP x,y specifies the coordinates of the end points of the vector movement with
respect to the starting point. The command CR r,q,d defines a circular arc with a radius r, starting
angle of q, and a traversed angle d. The notation for q is that zero corresponds to the positive
horizontal direction, and for both q and d, the counter-clockwise (CCW) rotation is positive.
Up to 511 segments of CR or VP may be specified in a single sequence and must be ended with
the command VE. 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 VP and CR commands which
were stored in the buffer prior to the start of the motion. To stop the motion, use the instructions
STS or AB1. ST stops motion at the specified deceleration. AB1 aborts the motion
instantaneously.
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
VE command is not given, an 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-1600 sequence
buffer to ensure continuous motion. If the controller receives no additional motion segments and
no VE 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 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.

Additional commands

The commands VS n, VA n and VD n are used for specifying the vector speed, acceleration, and
deceleration.
VT is the s curve smoothing constant used with coordinated motion.
Specifying Vector Speed for Each Segment:
The vector speed may be specified by the immediate command VS. It can also be attached to a
motion segment with the instructions
The first command, <n, is equivalent to commanding VSn at the start of the given segment and
will cause an acceleration toward the new commanded speeds, subjects to the other constraints.
The second function, > m, requires the vector speed to reach the value m at the end of the
segment. Note that the function > m may start the deceleration within the given segment or during
84 • Chapter 6 Programming Motion
VP x,y < n >m
θ,δ
CR r, < n >m
DMC-1600