DMC-18x6 Command Reference
126
LI
FUNCTION: Linear Interpolation Distance
DESCRIPTION:
The LI a,b,c,d command specifies the incremental distance of travel for each axis in the Linear
Interpolation (LM) mode. LI parameters are relative distances given with respect to the
current axis positions. Up to 511 LI specifications may be given ahead of the Begin Sequence
(BGS) command. Additional LI commands may be sent during motion when the controller
sequence buffer frees additional spaces for new vector segments. The Linear End (LE)
command must be given after the last LI specification in a sequence. This command tells the
controller to decelerate to a stop at the last LI command. It is the responsibility of the user to
keep enough LI segments in the controller's sequence buffer to ensure continuous motion.
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. It should be noted that the controller computes the
vector speed based on the axes specified in the LM mode. For example, LM ABC designates
linear interpolation for the A,B and C axes. The speed of these axes will be computed from
VS
2
=AS
2
+BS
2
+CS
2
where AS, BS and CS are the speed of the A,B and C axes. If the LI
command specifies only A and B, the speed of C will still be used in the vector calculations.
The controller always uses the axis specifications from LM, not LI, to compute the speed.
The parameter n is optional and can be used to define the vector speed that is attached to the
motion segment.
The LI command will apply to the selected coordinate system, S or T. To select the coordinate
system, use the command CAS or CAT.
ARGUMENTS: LI n,n,n,n,n,n,n,n <o >p or
LIA=n where
n is a signed integer in the range -8,388,607 to 8,388,607 and represents the incremental move
distance (at least one n must be non-zero).
o specifies a vector speed to be taken into effect at the execution of the linear segment. o is an
unsigned even integer between 0 and 22,000,000 for servo motor operation and between 0 and
6,000,000 for stepper motors.
p specifies a vector speed to be achieved at the end of the linear segment. Based on vector accel
and decal rates, p is an unsigned even integer between 0 and 22,000,000 for servos, and
between 0 and 6,000,000 for steppers.
USAGE: DEFAULTS:
While Moving
Yes
Default Value
-
In a Program
Yes
Default Format
-
Command Line
Yes
Controller Usage
ALL CONTROLLERS
RELATED COMMANDS:
Linear end
Linear Interpolation Mode
EXAMPLES:
LM ABC
Specify linear interpolation mode
LI 1000,2000,3000
Specify distance
LE Last
segment
BGS Begin
sequence
