Owner manual

Rockwell Automation Publication GMSI10-UM002D-EN-E - August 2012 287
Chapter 11
FRF Frequency Response Function Extension
Module
The Frequency Response Function (FRF) extension module is an optional
module for the Enpac 2500 data collector. You install the extension module with
the FRF Frequency Response PCMCIA memory card.
See Installing Optional Extension Modules
on page 189 for installation
instructions.
The Enpac 2500 data collector FRF extension module lets you determine the
natural frequencies of a machine or structure in a more sophisticated manner
than the Bump Test module. Rather than simply detecting the frequencies where
resonances occur, it captures information about the frequency response of the
structure being tested.
• You can use the FRF data in conjunction with a modal analysis software
package to model the way the structure reacts to forces applied to it.
• You can use the FRF module to capture information about how a machine
moves when it is running. You can use this information with the Operation
Deflection Shape (ODS) analysis software.
The FRF module includes the following features:
• Simple selection of measurement type from a list of predefined options, for
example, mobility, stiffness, and apparent mass.
• FRF trace colored green or red to illustrate high or low coherence.
• Optional automatic parameter setting for input ranges, number of lines,
and windowing.
• Compatibility with ODS analysis software.
Topic Page
Newtons Law and Apparent Mass 288
Setting Up an FRF Measurement 288
FRF Module Setup 290
Collect FRF Data 294
Field Calibration 297
Saving, Reviewing, and Deleting FRF Measurements 299
IMPORTANT
The FRF extension module is for Offroute/unscheduled measurements only.
The Emonitor software does not import this type of data.