Chapter 4 What You Need to Know about Moves
NI-Motion User Manual 4-10 ni.com
You can calculate the minimum acceleration increment in RPS/s with the
following formula:
where Amin = 1/65,536 counts/sample2 or steps/sample2
Ts = sample period in seconds per sample
R = counts or steps per revolution
or
For a typical servo axis with 2,000 counts or steps per revolution operating
at the 250 µs update rate, calculate the minimum RPS/s increment using the
following equation:
or
Table 4-3. Acceleration Update Rate in RPS/s
Update Rate MAX MIN
Calculation Based
on Units
62.5 µs 2,048,000,000 counts/sec23906 counts/sec2±RPS/smax = MAX×1/r
where r = counts/revolution
125 µs 2,048,000,000 counts/sec2977 counts/sec2
187.5 µs 910,222,222 counts/sec2434 counts/sec2
250 µs 512,000,000 counts/sec2244 counts/sec2
312.5 µs 327,680,000 counts/sec2156 counts/sec2±RPS/smin = MIN×1/r
where r = counts/revolution
375 µs 227,555,556 counts/sec2109 counts/sec2
437.5 µs 167,183,673 counts/sec280 counts/sec2
500 µs 128,000,000 counts/sec261 counts/sec2
RPS/s Amin 1
Ts
-----


2
×1
R
---


×=
RPM/s MIN 1
R
---
×=
1
65,536
----------------

1
250µs
---------------


21
2000
------------
×× 0.122070 RPS/s=
244 1
2000
------------
×0.122=