Allen-Bradley 1444-TSCX02-02RB User Manual page 143

Table 29 - Tracking Filters (continued)
Parameter
Measurement Units
Signal Detection
Measurement Resolution Speed 0/1
Values Comment
See Help comments Select the Engineering Units for the Tracking Filter measurements. These measurements are the
units that are applied to all enabled tracking filters for the channel.
The rules for Units selection, which is based on the Xdcr Units, are provided in the following table.
CLASS
Temperature
Pressure
Flow
Angle
Current
Energy
Frequency
Power
Voltage
Acceleration
Velocity
Length
For any acceleration, velocity or displacement (length) units the measurement can include any
required integration (or differentiation) simply by selecting the appropriate output units.
Displacement
m
mm
micron
inch
mil
Select from: Select the signal detection method for all Tracking Filter magnitude measurements for this
• Peak channel.
• Peak to Peak
A Tracking Filter is measured over a number of cycles or shaft revolutions, not from an
• RMS
instantaneous sample. It isn't possible to measure the actual "true" deflection of any single cycle.
Consequently, the selections are (scaled) Peak, (scaled) Peak to Peak, and RMS.
However, if the filtered signal is such that only the sine-wave of the order of interest remains, then
the "scaled" RMS equates to the "true" peak, or peak to peak measurement. The key difference
remains that the Tracking Filter is resolved from an extended data set, so the result does not equate
to the "true" peak or peak to peak measure of a signal that is not consistent throughout the
sample.
1...256 Enter the number of revolutions (bandwidth) to be applied to all tracking filters on this channel
that are defined for use with this tacho (0/1).
• The Number of Revolutions (over which the order results are calculated) determines the
narrowness of the filter, with more revolutions resulting in a sharper/narrower, more effective,
filter. However:
– A high number of revolutions results in an accurate measurement of the specified order.
– A low number of revolutions results in a broad filter that passes signals other than the
• A typical value is 10 (the default). A high value is 30, but values up to 256 are possible.
Rockwell Automation Publication 1444-UM001D-EN-P - June 2018
CHANGE EU OPTION
No change
Change in class only
Selections per following table
Velocity
 
m/s
mm/s
inch/s
However, at low speeds a high number of revolutions settings can slow the measurement
response to changes.
specified order value. However, the lower the number of orders the more responsive it is to
changes.
Measurement Definition
Acceleration
2
 
m/s
2
mm/s
2
inch/s
g
mg
Chapter 4
143