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Rockwell Automation Publication 1441-UM006A-EN-P - May 2011
Chapter 2
Run Up/Coast Down Extension Module
Spacing
Controls the spacing between collected spectra:
•
Δ
rpm is a fixed speed change between spectra.
•
%
Δ
rpm is a percentage speed change between spectra.
•
Δ
Time is a fixed time interval between spectra.
•
Δ
rpm +
Δ
Time is a combination of speed and time interval settings. If
speed stops changing then spectra are calculated using the Time Interval
value.
•
%
Δ
rpm +
Δ
Time is a combination of speed and time interval settings.
If speed stops changing then spectra are calculated using the Time
Interval value.
Δ
rpm
%
Δ
rpm
Δ
Time
Δ
rpm +
Δ
Time
%
Δ
rpm +
Δ
Time
Your selection affects the Speed Interval
and Time Interval settings.
Speed Interval (RPM) Sets the speed interval used in calculating FFT spectra.
This parameter not used when Spacing is set to
Δ
Time.
1…240 rpm
Time Interval (sec)
Sets the time interval used in calculating FFT spectra.
This parameter is not used when Spacing is set to
Δ
RPM and %
Δ
RPM.
.001…604800 s
Display Units
Sets the Y-axis units.
The available units depends on the transducer used to collect data.
Run Up/Coast Down Setup Parameters on page 18
.
Detection
Sets the signal detection and scaling display for the plot:
•
Peak - Measured RMS value multiplied by the square root of two (1.4142).
•
Pk-Pk - Measured RMS value multiplied by two times the square root of
two (2.8284).
•
RMS - Root mean squared signal level of the input signal.
RMS
Peak
PkPk
Lines
The number of lines (bins) of resolution for the FFT spectra. The larger the
number of lines, the better the frequency resolution of the measured data in the
spectra. Similarly, the higher the number of lines, the longer it takes to display
the spectra in the plot.
100
200
400
800
1600
3200
6400
12800
X-axis
Sets the x-axis frequency units for displaying spectra/FFT data:
•
Hz - Displays spectra in Hertz, cycles per second.
•
CPM - Displays spectra in cycles per minute.
•
Orders - Displays spectra in orders of the operating speed.
Hz
CPM
Orders
Your selection affects the Freq Range and
LF Cutoff parameters.
Freq. Range (EU)
The maximum frequency for the measurement.
The frequency range is determined by the X-axis parameter.
10…2000 Hz
600…120000 CPM
.001…166 Orders
Table 7 - Waterfall Plot Parameters
Parameter Name
Description
Values/Comments