Rockwell Automation 1441-PEN25-Z Enpac 2500 Data Collector - Manual (Page 77)

Rockwell Automation Publication GMSI10-UM002D-EN-E - August 2012 77
Setting Up Measurements Chapter 2
You can choose a frequency reference item as your machine speed reference. This
allows for machine speeds to be stored and retrieved dynamically. The Enpac
supports two types of frequency types: speed reference and linear rotational.
If you want to use a collected measurement from the Enpac to set the machine
speed, you have two options.
• Use a manual entry process measurement to enter machine speed by
reading it from any instrument in your plant. The measurement can then
be referenced for the machine speed, and would be updated every time you
unload that measurement.
• Use a measurement with Order normalization checked in the collection
specification. The machine speed from an internal or external tachometer
will be used for the machine speed. If the Order normalization checkbox is
not checked, the Enpac will use a fixed Fmax value and will not calculate
the Fmax based on the current speed of the machine.
Emonitor orders all the measurements in the route so that the dependent
machine speed measurement is collected first. This way, the route is set up for the
most accurate machine speed entry, and the measurements refer to the correct
machine speed. The band alarms and frequency labels adjust to changes in the
machines speed.
To set up the Speed Reference Frequency for the Enpac, double-click in the
Definition column in the Speed Reference row in the Frequency Item pane. The
Speed Reference Frequency dialog appears.
TIP The Orders normalization checkbox does not produce Orders
Tracking measurements when used with speed references.
These options are not supported in the
Enpac 2500.