Rockwell Automation 1441-PEN25-Z Enpac 2500 Data Collector - Manual (Page 82)

82 Rockwell Automation Publication GMSI10-UM002D-EN-E - August 2012
Chapter 2 Setting Up Measurements
• Phase and magnitude measurements at orders require a trigger signal. This
can be from the internal laser tachometer or from an external trigger source
such as a key phasor.
To Set Up Multiple Measurement Definitions for Magnitude and Phase
You create only one measurement definition for magnitude and phase at each
order. The Also collect phase data checkbox in the Collection Specification
dialog determines whether you also want to collect phase as well as magnitude
data.
1. Create a new measurement definition by selecting Magnitude in the Data
Type column in the Measurement Definition pane.
2. Select the units for the measurement definition, using a dynamic unit such
as g, m/s2, ips, mm/s, mils, um, or V.
3. Select the measurement filter. To collect the magnitude and phase at an
order, select a band filter centered on the order. For example, select (create
if necessary) a first order band filter with a Low cutoff of 0.8 Orders, and a
High cutoff of 1.2 Orders.
Refer to Measurement Filters on page 63 for details and the examples on
the following pages.
4. Select the collection specification. You must check the Also collect phase
data checkbox in the Collection Specification dialog so the data collector
collects phase at orders.
5. Select the storage specification. The first measurement definition is now
complete.
6. If you want to create more than one measurement, copy the measurement
definition by selecting the correct row and choosing Edit > Copy.
7. Move down to the next empty row in the measurement definition
spreadsheet, and choose Edit > Paste to paste the copied measurement
definition.
8. Edit the new measurement definition by changing the measurement filter.
Select a band filter centered on the next order.
9. Repeat steps 6 and 7 to create measurement definitions for the desired
orders. You can then include these measurement definitions in a list and
load it to the data collector. Remember that you must have a trigger signal
to collect magnitude and phase at an order.
IMPORTANT It is very important that order band filters be centered on the order. For
example, 0.7…1.3 orders, 0.8…1.2 orders, 0.9…1.1 orders. If you do not
center the band filters, magnitude and phase readings may not be accurate.