Rockwell Automation Allen-Bradley PowerMonitor 5000 Unit - Page 192

192 Rockwell Automation Publication 1426-UM001J-EN-P - August 2019
Chapter 7 Logic Functions
• Percent of Sliding Reference - the selected parameter is compared against
the sliding average of that parameter. This evaluation type can identify
rapid variations from a nominal value that changes relatively slowly over
time. You configure the sliding average interval in minutes by setting the
value of the Relative_Setpoint_Interval_m tag, found in the
Configuration.PowerQuality Data Table
on page 327 which has a range of
1…1440 minutes (24 hours). One Relative_Setpoint_Interval is used for
all setpoints. The sliding average is updated at a rate of one second per
minute of interval. For example, a 5 minute sliding average interval
updates every 5 seconds. You configure the percentage of the sliding
average in the Threshold tag for each setpoint. The Reference tag is not
used in the Percent of Sliding Reference evaluation type.
Simple Setpoint Logic (all models)
The PowerMonitor 5000 unit provides three test conditions for setpoint logic.
Any parameter type is permitted to be used with any test condition. Be sure to
test the operation of your setpoint setup to assure the desired operation.
Greater Than
A Greater Than setpoint test condition arms the setpoint for activation when the
monitored value is greater than the threshold, and dis-arms the setpoint when the
value is less than the threshold less the hysteresis value. Figure 34
illustrates this
test condition. In Figure 34
, the setpoint is armed at point A, dis-armed at point
B, and armed at point C. Points d and f also arm the setpoint but the value
decreases below the threshold at points e and g before the assert delay time passes.
Figure 34 - Greater Than Test Condition
Threshold
Hysteresis
Assert
Delay
Deassert
Delay
Setpoint
Status
A
B
C
a
b
c
d
ef
g
Assert
Delay
1
0
Selected
Parameter