Allen-Bradley 1440-SDM02-01RA, User Manual, Page: 70 / 168

70 Rockwell Automation Publication 1440-UM001D-EN-P - September 2016
Chapter 2 Configure the XM-124 Standard Dynamic Measurement Module
The gSE measurements can provide early detection of surface flaws in rolling
element bearings, metal-to-metal contacts, insufficient bearing lubrication, and
process-related problems, such as dry running, cavitation, flow change, and
internal recirculation.
Alternation of gSE measurement mode alternates between the standard and
gSE measurement sets every several seconds. This functionality is like the XM-
122 gSE Vibration module. In Alternating gSE mode, the four Band
measurements can be derived from either the standard or gSE FFT.
The Continuous gSE measurement mode performs the DC Bias, gSE Overall,
and gSE FFT measurements. The Continuous gSE mode also performs four
Band measurements, which are derived from the gSE FFT.
The Tracking Filter and Band Pass Filter measurement modes are designed
specifically for monitoring aeroderivative gas turbine engines, such as the
General Electric LM2500 engine.
The Tracking Filter measurement mode performs the DC Bias, Overall, FFT,
TWF, Tracking Filter magnitude, and phase measurements. This functionality
is similar to the Tracking Filter measurement set used by the XM-123
Aeroderivative module, except the XM-123 does not perform the FFT and
TWF measurements.
The Band Pass Filter measurement mode performs the DC Bias, Overall, FFT,
TWF, and Band Pass Filter measurements. This functionality is similar to the
Band Pass Filter measurement set used by the XM-123 Aeroderivative module,
except the XM-123 does not perform the FFT and TWF measurements.
The Thrust Position measurement mode performs a Thrust Position
measurement and the Standard measurement mode measurements. This
functionality contains the same set of measurements that are performed by the
XM-124 V6 firmware while the Thrust Position measurement is enabled. This
functionality is also like the position measurement that is performed by the
XM-320 Position module when it is configured in its Normal mode.
The Eccentricity measurement mode performs the DC Bias and Eccentricity
measurements. Eccentricity is the measure of the amount of bow in a rotor.
The lower the eccentricity value, the more straight the shaft. Rotor bow can be
a fixed mechanical bow, or it can be a temporary bow that is caused by uneven
thermal heating or simply by the weight of the rotor (gravity bow). The
Eccentricity measurement mode is suitable for virtually all types of rotating
and reciprocating machinery where rotor bow must be measured before or
during startup. This eccentricity measurement is the same as the eccentricity
measurement performed by the XM-120E Eccentricity module.
Signal Processing
The Signal Processing group box options apply to the Standard, Alternating
gSE, Tracking Filter, and Band Pass Filter measurement modes. These settings
affect the standard Overall, FFT, and TWF measurements.