Rockwell Automation 1404-M4_M5_M6_M8 Powermonitor 3000 User Manual, Firmware rev. 3.0 or LATER - Manual (Page 181)

Publication 1404-UM001F-EN-P - November 2009 181
Advanced Features Chapter 8
•
Auto-threshold set margin: range 1.0…100.0 per cent, default
20.0
•
Voltage trigger threshold: range 0.1…1000.0, default 10.0
•
Current trigger threshold: range 0.1…1000.0, default 10.0
Threshold Configuration
The power monitor compares voltage or current transients against a
threshold that you may set manually or command to be set
automatically. You select either voltage channels or current channels
with the Detection mode parameter.
When you issue the Auto-threshold set command, the power monitor
first determines if there is sufficient signal amplitude on the selected
voltage or current channels to set the threshold. If the signal
amplitude is greater than 10% of full-scale, the power monitor begins
timing the Auto-threshold set duration. During this time, it monitors
the selected channels, calculates an average transient index, and
decrements the Auto-threshold duration time remaining parameter. At
the end of this time, it combines the average transient index with the
Auto-threshold set margin and stores the result as the Voltage trigger
threshold or Current trigger threshold.
Threshold settings relate to both magnitude and duration of a
transient, so they are representative of the energy contained in a
transient. In most cases, use the automatic threshold calculation as a
starting point, by issuing an Auto-threshold set command. Then
manually adjust the selected threshold if you want to increase or
decrease the sensitivity.
The power monitor does not monitor for or capture transient data
until a threshold setting has been configured.
Reading Transient Analysis Metering Data
The Powermonitor 3000 M8 model presents 12 cycles of transient
metering results for each of up to 6 transient captures in the
Transient
Analysis Metering Results Parameters table. Transient analysis
metering data is not available via Modbus communication. This
read-only table of 14 floating-point elements contains the following
metering results and capture statistics:
•
Capture number: transient capture number associated with the
metering results. Range 1…6
•
Cycle number: which cycle in the capture is returned in this
read. Range 1…12