Contour Mode - Galil Motion Control DMC-21 5 Series User Manual

Contour Mode

The DMC-21x5 also provides a contouring mode. This mode allows any arbitrary position curve to be prescribed for
1 to 8 axes. This is ideal for following computer generated paths such as parabolic, spherical or user-defined
profiles. The path is not limited to straight line and arc segments and the path length may be infinite.
Specifying Contour Segments
The Contour Mode is specified with the CM command. Any axes that are not being used in the contouring mode
may be operated in other modes.
A contour is described by position increments which are described with the CD command over the time interval
defined by the DT command. The time interval is defined as 2
number between 1 and 8. The controller performs linear interpolation between the specified increments, where
one point is generated for each sample. If the time interval changes for each segment, the CD command can be
used to change the interval. Consider, for example, the trajectory shown in Figure 6.15. The position A may be
described by the points:
The same trajectory may be represented by the increments
Increment 1
Increment 2
Increment 3
When the controller receives the command to generate a trajectory along these points, it interpolates linearly
between the points. The resulting interpolated points include the position 12 at 1 msec, position 24 at 2 msec, etc.
The programmed commands to specify the above example are:
#main
CM A;
CD 48=2;
CD 240=3;
CD 48=4;
CD 0=0;
#wait;
WT 20
JP#wait,(_CM<>511);
EN;
Chapter 6 Programming Motion ▫ 63
Point 1
Point 2
Point 3
Point 4
DA=48
DA=240
DA=48
'specifies A axis for contour mode
'first position increment and time interval, 2^2ms
'second position increment and time interval, 2^3 ms
'third position increment and time interval, 2^4 ms
'end Contour buffer
'wait until path is done
'end program
POSITION
(COUNTS)
336
288
240
192
96
48
0
4 8
12
SEGMENT 1 SEGMENT 2
Figure 6.15: The Required Trajectory
n sample period (1 ms for TM1000), where n is a
A=0 at T=0ms
A=48 at T=4ms
A=288 at T=12ms
A=336 at T=28ms
Time=4
Time=8
Time=16
TIME (ms)
28
20 24
16
SEGMENT 3
DT=2
DT=3
DT=4
DMC-21x5 User Manual 1.0a1