Rockwell Automation 1441-PEN25-Z Enpac 2500 Data Collector - Manual (Page 76)

76 Rockwell Automation Publication GMSI10-UM002D-EN-E - August 2012
Chapter 2 Setting Up Measurements
For Orders Track data collection, you are required to use a trigger to continually
determine machine speed.
Orders tracking analysis can be used effectively to diagnose the vibrations of
variable speed machines. The orders tracking yields data in the revolution
domain, not the time domain. In an orders spectrum, signals that are periodic in
the revolution domain appear as peaks and orders or harmonic components
remain fixed in their position through speed changes. This is a clear advantage
when comparing the characteristics of variable speed machines over a period of
time.
Using Frequency Items for the Diagnostic Frequency Cursor
Using the Enpac 2500, you set up frequency items in Emonitor and download
them to the Enpac. Then, you can review the data using the Diagnostic
Frequencies cursor. This feature allows you to diagnose the peaks you see in the
Enpac using the frequency items from the host software.
In order to load the Diagnostic Frequency labels, you must check the Load
Frequency Labels checkbox in the Load Options dialog.
Setting Up Speed References
The Enpac can determine the speed using speed references in Emonitor. The
speed reference value is used by the frequency items to calculate the Fmax of the
dependent measurements.
To set up speed references in Emonitor, double-click in the RPM column in the
Location pane. The following dialog appears.