Rockwell Automation 1440-VST02-01RA XM-120 Eccentricity Module - Manual (Page 54)

Publication GMSI10-UM010C-EN-P - May 2010
46 Configuration Parameters
TIP
The Waveform Period and the Number of Points must
be configured such that the sampling rate (Number of
Points/Waveform Period) is from 0.32 Hz to 187.5 Hz.
The module will automatically use 187.5 Hz when the
sampling rate is above 93.75, resulting in waveforms
collected with a different period than specified.
The table below shows examples. The entries in the table
are the actual sampling rate (samples per second) and
period corresponding to the waveform period and number
of points.
Note that the signal processing hardware applies a low pass
filter of 20 Hz to the input signal. Therefore the
eccentricity measurements taken at sampling rates above
51.2 samples/second will reflect this low pass filter.
Number of Points
Requested
Period(s)
256 512 1024 2048
Actual
Sampling
Rate
Actual
Period
Actual
Sampling
Rate
Actual
Period
Actual
Sampling
Rate
Actual
Period
Actual
Sampling
Rate
Actual
Period
5 51.2 5.0 187.5 2.73 187.5 5.46 187.5 10.92
10 25.6 10.0 51.2 10.0 187.5 5.46 187.5 10.92
25 10.24 25.0 20.48 25.0 40.96 25.0 81.92 25.0
100 2.56 100.0 5.12 100.0 10.24 100.0 20.48 100.0
800 0.32 800 0.64 800.0 1.28 800.0 2.56 800.0