Rockwell Automation 1440-VLF02-01RA XM-121 Absolute Shaft Module - Manual (Page 151)

Publication GMSI10-UM014D-EN-P - May 2010
Glossary 143
RMS (square root of the mean of the square of the values) are the most
common methods of signal detection.
slave device
A device that receives and responds to messages from a Master device but
does not initiate communication. Slave devices include the XM measurement
modules, such as the XM-120 Dynamic Measurement module and the XM-320
Position module.
startup/coast-down trend
A speed-base trend that is collected in an XM module during the startup or
coast-down of a machine when the measured machine speed crosses into a
defined speed range.
Strobe
See Bit-Strobe.
transducer
A transducer is a device for making measurements. These include
accelerometers, velocity pickups, displacement probes, and temperature
sensors.
trend
A set of records of one or more measurement parameter(s) collected at regular
intervals based on time or speed.
trigger
An event that prompts the collection of trend data.
triggered trend
A time-based trend that is collected in an XM module when a relay on the XM
module is activated, or when the module receives a trigger event.
virtual relay
A virtual relay is a non-physical relay. It has the same capabilities (monitor
alarms, activation delay, change status) as a physical relay only without any
physical or electrical output. The virtual relay provides additional relay status
inputs to a controller, PLC, or an XM-440 Master Relay module (firmware
revision 5.0 and later).