The NumberOfTransitions Aggregate defined in Table 35 returns a count of the number of transition the Variable had during the interval. If one or more raw values are Bad, they are not included in the count, and the Aggregate StatusCode is determined using the StatusCode Calculation (see 5.3) for nontime based Aggregates.
The earliest transition shall be calculated by comparing the earliest nonBad value in the interval to the previous nonBad value. A transition occurred if no previous nonBad value exists or if the earliest nonBad value is different. The endTime is not considered part of the interval, so a transition occurring at the endTime is not included.
Unless otherwise indicated, StatusCodes are Good, Calculated.
Table 35 – NumberOfTransitions Aggregate summary
NumberOfTransitions Aggregate Characteristics 

Type 
Calculated 

Data Type 
Int32 (negative values are not allowed) 

Use Bounds 
Custom, a nonBad value prior to the interval is used 

Timestamp 
StartTime 



StatusCode Calculations 

Calculation Method 
PercentValues 

Partial 
Set Sometimes If an interval is not a complete interval 

Calculated 
Set Always 

Interpolated 
Not Set 

Raw 
Not Set 

Multi Value 
Not Set 





StatusCode Common Special Cases 

Before Start of Data 
Bad_NoData 

After End of Data 
Bad_NoData 

No Start Bound 
Treat the beginning value as Bad_NoData and compute the Aggregate 

No End Bound 
Treat the ending value as Bad_NoData and compute the Aggregate 

Bound Bad 
Use as value and compute the Aggregate as defined 

Bound Uncertain 
Use as value and compute the Aggregate as defined 