Galil Motion Control DMC-42 0 Series, User Manual

Page: 146 / 218

X-Y Table Controller
An X-Y-Z system must cut the pattern shown in Figure 7.2. The X-Y table moves the plate while the Z-axis raises and
lowers the cutting tool.
The solid curves in Figure 7.2 indicate sections where cutting takes place. Those must be performed at a feed rate
of 1 inch per second. The dashed line corresponds to non-cutting moves and should be performed at 5 inch per
second. The acceleration rate is 0.1 g.
The motion starts at point A, with the Z-axis raised. An X-Y motion to point B is followed by lowering the Z-axis and
performing a cut along the circle. Once the circular motion is completed, the Z-axis is raised and the motion
continues to point C, etc.
Assume that all of the 3 axes are driven by lead screws with 10 turns-per-inch pitch. Also assume encoder
resolution of 1000 lines per revolution. This results in the relationship:
1 inch = 40,000 counts
and the speeds of
1 in/sec = 40,000 count/sec
5 in/sec = 200,000 count/sec
an acceleration rate of 0.1g equals
0.1g = 38.6 in/s2 = 1,544,000 count/s 2
Note that the circular path has a radius of 2” or 80000 counts, and the motion starts at the angle of 270° and
traverses 360° in the CW (negative direction). Such a path is specified with the instruction
CR 80000,270,-360
Further assume that the Z must move 2” at a linear speed of 2” per second. The required motion is performed by
the following instructions:
INSTRUCTION FUNCTION
#A Label
VM XY Circular interpolation for XY
VP 160000,160000 Positions
VE
End Vector Motion
VS 200000 Vector Speed
VA 1544000 Vector Acceleration
BGS Start Motion
AMS When motion is complete
PR,,-80000 Move Z down
SP,,80000 Z speed
BGZ Start Z motion
AMZ
Wait for completion of Z motion
CR 80000,270,-360 Circle
VE
VS 40000
Feed rate
BGS Start circular move
AMS Wait for completion
PR,,80000 Move Z up
BGZ Start Z move
AMZ
Wait for Z completion
PR -21600 Move X
SP 20000 Speed X
BGX Start X
AMX Wait for X completion
PR,,-80000 Lower Z
BGZ
AMZ
CR 80000,270,-360
Z second circle move
VE
Chapter 7 Application Programming ▫ 142 DMC-42x0 User Manual