Rockwell Automation 1426 PowerMonitor 5000 Unit - Manual (Page 158)

158 Rockwell Automation Publication 1426-UM001F-EN-P - November 2013
Chapter 7 Logic Functions
Operation
A PowerMonitor 5000 unit setpoint continually monitors the selected parameter
and evaluates its value against the configured test condition, evaluation types,
threshold, and hysteresis values. The setpoint is armed when the parameter value
satisfies the test condition. A setpoint activates when it has been armed for at
least the assert delay time. The setpoint is dis-armed when the parameter value no
longer satisfies the test condition (including a dead band defined by the hysteresis
value), and de-activates when it has been dis-armed for at least the deassert delay
time.
Each setpoint can be tied to an output action, such as energizing a relay output or
clearing a value. The M5 model has 10 setpoints. The M6 model has 20 setpoints.
Also, in the M6 model, setpoints can be used as inputs to up to 10 logic gates,
which lets you combine setpoints to take specified actions.
The power monitor provides setpoint data including status of each setpoint,
statistics relating to setpoint operations, and a setpoint history log.
Evaluation Types
The PowerMonitor 5000 M5 model provides two evaluation types for setpoints:
• Magnitude - the selected parameter is compared against a fixed value
configured by you in the Threshold tag for the setpoint. Magnitude is the
default selection and is typically used with metering values that are analog
in nature.
• State - the selected parameter is compared against a Boolean value (0…1)
configured by you in the Threshold tag for the setpoint. State is typically
used with discrete parameter values that are either off (0) of on (1).
The PowerMonitor 5000 M6 model provides two additional evaluation types:
• Percent of Reference - the selected parameter is compared against a
percentage of a fixed nominal reference value. You configure a nominal
value in the Reference Value tag for the setpoint, and configure the
percentage in the Threshold tag for the setpoint. This operates similar to
the Magnitude evaluation type but the power monitor, rather than you,
calculates the percentage of the nominal value.
• Percent of Sliding Reference - the selected parameter is compared against
that parameter’s own sliding average. 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 which has a range of 1…1440
minutes (24 hours). A single 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.