User`s manual

7-42 Motion Mate™ DSM314 for Series 90™-30 PLCs User's Manual – January 2001 GFK-1742A
7
Multi-axis Programming
Sync Blocks can be used in a multi-axis program to synchronize the axis motion commands at
positions where timing is critical.
Example 18: Multi-axis Programming
This example assumes that axis 1 controls vertical motion and axis 2 controls horizontal motion.
The objective is to move a piece of material from point A to point E as quickly as possible while
avoiding the obstacle that prevents a direct move between those points.
A simple way would be to move straight up from point A to point C, and then from point C to
point E. This sequence, however, wastes time. A better way would begin the horizontal
movement before reaching point C. It has been determined that after axis 1 has moved to a
position of 30,000, user units (to point B), axis 2 could then start and still clear the obstacle. The
program segment could be programmed as follows:
10: CMOVE AXIS1 30000, INCR, LINEAR
20: SYNC
PMOVE AXIS1 50000, INCR, LINEAR
PMOVE AXIS2 120000, INCR, LINEAR
When Block 10 is executed, axis 1 begins its 30,000-unit move while axis 2 pauses. When the
axis 1 move completes, two things occur: axis 1 begins the 50,000-unit PMOVE commanded in
Block 20 (SYNC) without stopping (because the first move was a CMOVE), and axis 2 begins its
120,000-unit move. In the figure below, the axis 1 first move transfers the part from point A to
point B. At point B, axis 1 continues moving (performing its second move) and axis 2 begins its
move, bringing the part to point D. Axis 1 completes its second move at point D and stops;
however, axis 2 continues, and moves the part to point E.
A
XIS 2
O
BSTACLE
B
A
D
120,000
0
a45271
80,000
30,000
AXIS 1
0
E
Part
C
Move 1
Move 2
Figure 7-22. Multi-axis Programming Example