Calculated Points are a specialized versions of Points. Just like Points they query data points for data but, where a single Point retrieves data from a single data point, a Calculated Point can retrieve data from multiple points. Upon receiving the requested data, the Calculated Point performs a calculation on the data and then stores the result of that calculation into a history file. The Points used by a Calculated Point must be defined in a Point section within the configuration file.
Calculated Points are not nested inside any other section. They are contained within a single section that starts with <CalcPoints> and ends with </CalcPoints>.
Section Parameters
These parameters are unique to Calculated Points:
Point Name – A unique text value assigned to the calculation.
Description – A brief description of the calculation, contained within double-quotes.
Update IntSec– The frequency in seconds in which the calculation is performed.
These parameters are in common with regular Points:
Number of Entries– The maximum number of history records stored for this calculation.
Auto or Optimized: Sets the Interval to Hourly and records 336 hourly records, 60 daily records, and 120 monthly into history.
Numeric Value: Sets the maximum number to the value indicated
Default (-): Designated by a hyphen, default stores only the last record.
Value Type–
Accumulated, Accum, Total, Totalize, Meter, or Metered: An aggregate value for the specified Interval is recorded in history.
Minimum or Min: The lowest value received in the specified Interval is recorded in history.
Maximum or Max: The highest value received in the specified Interval is recorded in history.
Average or Avg: The average of all values received in the specified Interval is recorded in history.
Instantaneous, Instant, Inst, or (-): The last value received in the specified Interval is recorded in history. If no value type is specified, it will default to this.
Interval– The frequency in which the result of the calculation is stored in history.
Minute
Hour or Hourly
Day or Daily
Month or Monthly
Multiplier– Multiplies the Interval by the value indicated. The default value, indicated with a hyphen, is 1. (An hourly interval with a multiplier of 3 would record entries 3 times an hour, or every 20 minutes.)
Rollover– Some points return an accumulating value that resets to zero once it reaches a maximum value (eg, a meter). This setting adds the accumulated value reached at the reset to the values now received. The default, designated by a hyphen, is zero.
This parameter defines the actual calculation:
Formula– The arithmetic formula the Display Server is to calculate and store.
Comments are denoted by a single-quote (') and may be ended by a single-quote or a line break.
Values containing spaces or tabs must be enclosed in double-quotes (") before and after.
1
<CalcPoints>
2
3
' Update Num of Value
4
'Point Name Description IntSec Entries Type Interval Multiplier Rollover Equation
