Table of Contents
Advertisement
© National Instruments Corporation
You can calculate the minimum acceleration increment with the following
formula:
minimum acceleration/deceleration
where
Amin = 1/65,536 counts/sample
Ts = sample period in seconds per sample
For a typical servo axis with 2,000 counts per revolution operating at the
250 µs update rate, calculate the minimum acceleration/deceleration
increment using the following equation:
1
-------------- -
65536
You can calculate the maximum acceleration/deceleration using the
following equation:
maximum acceleration/deceleration
where
Amax = 32 counts/sample
Ts = sample period in seconds per sample
and is constrained according to the following equations:
acceleration ≤ 256 × deceleration
deceleration ≤ 65536 × acceleration
NI 73xx
Acceleration in RPS/s
Acceleration and deceleration values in RPS/s are converted to an internal
16.16 fixed-point format in units of counts/sample
being used by the trajectory generator.
Table 4-3 shows the minimum and maximum acceleration update rates in
2
counts/sec
.
Chapter 4
2
1
×
244 counts/second
-------------- -
=
250µs
2
4-9
What You Need to Know about Moves
2
1
×
Amin
---- -
=
Ts
2
2
or steps/sample
2
2
1
×
Amax
---- -
=
Ts
2
or steps/sample
NI-Motion User Manual
2
before
Advertisement
Table of Contents
