Table of Contents
Advertisement
Chapter 4
What You Need to Know about Moves
If the distance of the move is too small, it may not be possible to reach the
Note
commanded maximum move constraints. In such instances, NI-Motion adjusts the move
constraints lower to reach the commanded position.
The conversion from floating-point to fixed-point is performed on the host
Note
computer, not on the motion controller. To load arc functions from onboard variables,
you must use the 16.16 fixed-point representation for all angles.
NI-Motion User Manual
NI 73xx
Arc Angles in Degrees
The Load Circular Arc, Load Helical Arc, and Load Spherical Arc
functions take angle parameters in degrees as double-precision
floating-point values. These values are converted to an internal
16.16 fixed-point representation where the integer part corresponds to
multiples of 45° (for example, 360° is represented as 0x0008 0000).
Use the following formula to convert from floating-point to fixed point:
where
Q = quotient, the integer multiple of 45°
R = remainder
Angle in 16.16 format
For example, 94.7° is represented in 16.16 format as follows:
Angle in 16.16 format
The minimum angular increment is
Angle in degrees
--------------------------------------- -
=
45°
·
Q.
=
4.7°
×
2.
65,536
--------- -
=
45°
1
×
45°
0.000687°
--------------- -
=
65.536
4-12
Q
R
+
R
×
65,536
------- -
45°
0x0002.1ABD
=
ni.com
Advertisement
Table of Contents
