Behavior - Allen-Bradley 1444-TSCX02-02RB User Manual

Appendix A CIP Objects
432

Behavior

Smax Measurements
In an XY application, the Smax result (magnitude and phase) is calculated
using the individual overall results and not at the sample level. Using the two
(orthogonal) processed scalar values in this way corresponds to 'Method A' in
the International Standards. Using method A:
• The Smax amplitude can be overestimated, but not under estimated.
• Any calculated phase angle is in the range 0 to 90°.
If the two scalar values are identical, the phase reports 45°.
If the first channel of the pair has the larger amplitude, the phase angle reads <
45°.
If the second channel of the pair has the largest amplitude, the phase angle
reads > 45°.
Shaft Absolute Vibration Measurements
When configured in this mode the calculation of absolute shaft vibration is
performed at a sample level. This method is necessary because any simpler
method that is based on overall values could be misleading as to the actual,
absolute vibration amplitudes.
Rockwell Automation Publication 1444-UM001D-EN-P - June 2018