National Instruments BridgeVIEW - Manual (Page 410)

Appendix B Citadel and Open Database Connectivity
© National Instruments Corporation B-5 BridgeVIEW User Manual
These data transforms allow you to directly calculate and retrieve complex
information from the database such as averages and standard deviations.
This time saving feature eliminates the need of extracting raw data first, and
then massaging it in another application to come up with the needed
information.
Table B-1. Data Transform Commands
Data Transform Command Description
Min{tag name} Returns the minimum for tag name
across the interval.
Max{tag name} Returns the maximum for tag name
across the interval.
Avg{tag name} Returns the average for tag name across
the interval.
StDev{tag name} Returns the standard deviation for tag
name across the interval.
Starts{tag name} Returns the number of starts (number of
transitions from OFF to ON) for tag
name across the interval.
Stops{Datapoint} Returns the number of stops (number of
transitions from ON to OFF) for
Datapoint across the interval.
ETM{Datapoint} Returns the amount of time Datapoint
was in the ON state across the interval.
Qual{Datapoint} There might be gaps in the historical
data threads in Citadel because of
machine shutdown or BridgeVIEW
shutdown. Qual returns the ratio of time
for which valid data exists for a
datapoint across the interval, to the
length of the interval itself. Thus if
valid data exists for only one-half of the
interval, Qual would return 0.5.