User's Manual

PMAC User Manual
140 Setting Up a Coordinate System
The PMATCH function effectively inverts the equations contained in the Axis Definition statements for the
coordinate system, using motor commanded positions, and solves for axis commanded positions. If more
than one motor is assigned to the same axis (e.g. #1->10000X, #2->10000X), the commanded
position of the lower-numbered motor is used in the PMATCH calculations.
If variable I14 is equal to 1, the PMATCH function is executed automatically every time motion program
execution is started (on all R [run] and S [step] commands). It does not hurt to do a PMATCH function if
the positions already match, so use the card with I14=1.
Y
(in)
2"
4"
cts
in
Motor #2 (10,000 )
45
2) Scaling and Rotation
X (in)
Y (in)
3) Orthogonality Correction
1 arc min
(exaggerated)
X (in)
#1 -> 10000.00X - 2.91Y
#2 -> 10000.00Y
#1 -> 7071.07X - 7071.07Y
#2 -> 7071.07X + 7071.07Y
1) Scaling and Translation
#1 -> 10000X + 40000
#2 -> 10000Y + 20000
Motor #1 (10,000 )
cts
in
cts
in
Motor #2 (10,000 )
cts
in
Motor #2 (10,000 )
Motor #1 (10,000 )
cts
in
Motor #1 (10,000 )
cts
in
Figure 23 PMAC Coordinate Definition